Not really a new subject and I have read most everything in here on the subject. I just doing homework before I start digging into it.
Our 98 u270 (had it home 3 weeks) is having a charging issue and has a history of eating alternators. By the records I count 4 and she only has 45,000 miles. PO said that he put one on it 4 or 5 years ago. Yeah but he put like 500 miles a year on the coach. They last longer than that.
She stopped charging on me on the way home and I put an alternator on and it got us home. Even with a new 160 amp Bosch replacement the volt meter only showed 11.5 volts (no I haven't double checked with a meter yet). The posts on the new alternator were in a different position but I'm pretty sure I hooked it up right. There is battery, ignition and the other one! But I was in a gas station parking lot mid Atlanta. Stressed with a coach that wouldn't move. No electricity no gears! Ask me how I learned this lesson.
When we got home I purposely didn't plug it in. All the batteries are 4 years old so I wanted to see how they did. After sitting 3 weeks, she cranked right up. After running a while I noticed it was only charging 10 volts. Gauges were running amuck, auto level wouldn't work right tach pegged itself on 3000.Turned it off and sure enough she would not crank back without the boost button. So I know she was sucking from the batteries and lacking voltage.
A quick look through all the cables and everything appears dry, clean and tight. This coach is really clean underneath. Zero rust on anything, even the battery trays with wet batteries still have most of their paint.
I know I need to up my automotive electrical testing game a bit. I can wire houses all day but they don't have diodes and batteries and olms don't mean much there, its hot or its not. I understand that the isolator may be a good place to start. I'm not in a rush and I'm a pretty fair mechanic so I feel I should be able chase this down myself. I have a lot of things that need attention so don't be surprised if you see me start multiple posts.
Any help guidance or just moral support is well appreciated.
I am also new to this forum and if I do a no-no, just correct me and lead me. My wife says I'm trainable, with patience!
Thanks so much,
Not going to be much of a help, but figure anytime an alternator fails so often, the problem is likely outside of the alternator. But it is true there are some poor rebuilt alternators sold out there, as they only replace broken parts, so most of us like to find a local small rebuilder and keep our original, but that is too late for you.
Motorhomes have isolators that allow alternator to charge house & start battery banks, while keeping the two banks "isolated" from each other. In this case the alternator requires a separate small-wire that directly reads house battery voltage as the isolator keeps the alternator from seeing either battery voltage on its output cable. Foretravel uses another small-wire to 'excite' the alternator with ignition voltage. Normally our coaches require a not real popular. style of alternator called "Duvac" that has both of these two small wire connections on the back of the alternator's voltage regulator.
Sometimes, usually out of ignorance, non-Duvac alternators are installed with work arounds for the voltage sense and excite wires. And other times the two small wires are reversed or any combination of messing up.
Most alternators also have three styles of built-in voltage regulators: variable, 3-step, fixed. If using a diode-based isolator (most common), with the isolator's diodes reducing alternator voltage, the alternator usually outputs a higher-than-normal voltage, which after the isolator is lowered to a more friendly voltage for charging batteries.
I am writing because we all face a broken alternator at inopportune times and a readily available temp fix can keep us rolling for weeks if we want:
Run generator while driving, turn boost switch on, and let the inverter/charger power the start battery bank via the boost solenoid. Many of us have used this simple bypass for weeks until we get back to an opportune time to fix our alternator.
Hope you get to the bottom of alternator musical chairs.
If replacing the OEM alternator with another brand, make sure the pulleys are the same diameter. Alternators don't care for overspeeding. Most alternators from cars have small pulleys so they charge in stop and go traffic. Make sure the belts are not too tight. You should be able to rotate the belt 90 degrees with your fingers mid-span.
Pierce
Find the Isolator and try bypassing it . It has 3 post. Connect the alt wire to the engine battery post . And go from there. IMHO
Barry, we bought a direct replacement alternator i gave them the leese neville# number out of the FT manual! They crossed to brand new bosch 160 amp $500 one and i still have my old one, but it wasnt an original!. Had three wires, a big one(battery) and 2 small ones. The post marked I on the new one(marked ign on the old one) and as i said before, the other one! Not sure what it is or where it goes.
Our coach is going to need some love before we get her too far from home so she is sitting beside the shop plugged in for me to service everything and figure this out.
Im lost at the exciter wire! If i read correctly the alternator should be charging 14 .5 ish volts which is higher than the average car right? (12.5 ish volts)
Im gonna need to freshen up my meters and testing skill sets.
Do you think a Leece-Neville alternator would help is issue?
I saw a isolator for a fair price,.should i just buy the darn thing? Im gonna have the old alternator rebuilt and have a spare.
Belts fine and it has an idler pulley no i cant really adjust it. i used the old alternators pulley so it should be spinning correctly.
Jim, napa said that was a direct replacement for the leece neville. IDK,.has a 2 year warranty if its not right!
Replacement alternators have caused many problems for Forum members. If the person buying, or replacing, the alternator does not understand the Foretravel diode isolator charging system then they often end up either installing the wrong alternator or screwing up the wiring...or both.
Look at the diagram below. This is a screen shot taken from the top right corner of the B-2179 12 Volt Wiring Diagram, found in our Forum library. It shows a (U320) DUVAC alternator wiring setup, which is similar to the one installed in your U270 coach when it left the factory.
https://www.foreforums.com/index.php?action=media;sa=media;in=3300
Look at the DUVAC alternator in the diagram. It has 4 terminals on the back. The two large terminals are the B+ output, and the negative (-) ground. The B+ cable connects to the center post on the battery isolator. The negative ground cable connects to a large grounding bolt on the engine block.
The other two terminals are smaller. One terminal, usually marked SENSE (S) connects to a circuit breaker and then to the engine START battery post on the isolator. The other small terminal, called the "exciter", is usually marked IGN and goes into the wire loom where it eventually connects to a 12 volt power source that is only hot when the ignition switch is in the ON position.
These two small alternator terminals must be present and properly connected in order for your original OEM charging system to operate. If the alternator on your coach does not have these terminals, then it is not a DUVAC alternator. It is possible to make a non-DUVAC alternator work on your coach, but it requires modification of the stock wiring and/or a different type of battery isolating device.
If you post a photo of the back side of your alternator, it'll help us figure out how to get your charging system working. Don't start buying parts until you understand what you have now and if it can be made to work.
The link below takes you to a post (Reply #17) with photos of a OEM Leece Neville DUVAC alternator, just like the one that originally came on your coach.
Alternator, Isolator or both? (https://www.foreforums.com/index.php?topic=43830.msg442251#msg442251)
Thanks so much im gonna print and check through all this and see where im at. Unfortunately Saturday night i was.lucky to find anything much less an exact replacement. It may be that i need to go back to that very thing. Im not trying to upgrade. Just want it working and fixed!
If you can post the model number off the ID plate on your Bosch alternator that would help us help you.
I dont have access to the back of the alternator tonight.
I do have the bosch part number and the paperwork that was enclosed if i can figure out how to attach on here from my phone. Which does not appear to be possible! Is this not possible?
Its a bosch AL9960LH
Here's a picture of the back and a description of it.
AL9960LH - STS Diesel (https://stsdiesel.com/al9960lh/)
The Bosch AL9960LH alternator is a self-excited "1-wire" model. It does not have a SENSE terminal.
The "I" terminal is a INDICATOR connection. It is NOT a (hot with ignition switch ON) "EXCITE" terminal. Connecting the "I" terminal to a 12 volt source may damage the alternator or the internal regulator.
This alternator is NOT suitable for use with a diode based battery isolator. As noted earlier, it is possible to make this alternator work, but it will require modification of the OEM charging system.
If you still feel this way after "sleeping on it" then I can suggest a couple different options. It is up to you to decide if either one is of any interest.
Option 1: Keep the Bosch alternator and make it work. A "1-wire" alternator is designed to be very simple to install. All it requires is one output wire (hence the name) which is connected directly to the engine
start battery. The alternator grounds through the mounting bracket. You could replicate this "1-wire" alternator connection on your coach by following Mike's (Protech Racing) earlier suggestion to "Find the Isolator and try bypassing it. It has 3 posts. Connect the alt wire to the engine battery post." You would remove any other wires that are now attached to the alternator. By doing this you will have the Bosch alternator correctly wired, and (assuming it is not damaged from prior incorrect wiring) it should function properly. However, it will
only charge the engine start batteries. Depending on how you plan to use your coach, this might work fine. If you plan to normally stay in RV parks with shore power hookup, then your house (coach) batteries become much less important. They will be charged by your inverter/charger when you are connected to shore power (or running your generator), and they should have plenty of power to run the coach appliances when driving down the road. As a backup, you can always use the BOOST switch to connect both battery banks when the engine is running. With the BOOST switch on,
both start and house batteries will be charged by the alternator.
Option 1 with a upgrade: You can keep the Bosch alternator and replace the OEM diode based battery isolator with a different type of device, commonly called a "Smart Combiner". There are several to choose from. They can vary in price and complexity. Going this route will allow your charging system to operate automatically just like the original design, but with improved efficiency and some additional benefits. Forum members have a lot of experience with this kind of modification, and can help you with the choice of product and installation.
Option 2: Replace the Bosch alternator with a proper DUVAC model. Going this route will return your coach to the factory original automatic charging design. In all likelihood your battery isolator is just fine - we can tell you how to check it for proper operation. You will also need to verify that both the SENSE wire and the EXCITE wire are still present on your coach, and still connected correctly. This is also easy - we can tell you how.
You need to decide how you want to operate your coach, and how you want to correct the problem with your charging system.
And, a third option that is NOT automatic is to go KISS theory and install a simple marine ON-OFF switch.
Alternator B+ and chassis battery cable to one lug and house battery cable to the other lug.
ON, both battery banks are charged (by either alternator or inverter/charger). Also, high-amp "boost" function.
OFF and only chassis battery is charged from the alternator.
I installed mine at the foot of the bed so easy to select from inside.
Diode-based isolator in the trash.
Wow thanks so much guys, so much great information.
I am a KISS kind of guy but in this case I am going to make a few calls and see if I can get my money back from NAPA since what they sold me is not truly correct. then go from there.
Thanks again,
Yup, with a diode-based battery isolator, you MUST use an alternator with external SENSE WIRE.
Since the sense wire is on the chassis battery side of the isolator, it insures that the batteries receive the correct voltage.
You need to find out where all of those electrons are going.
One way to to disconnect all electric loads, then add them back one by one.
Quick question out of no where: Are you running something big on your inverter?
Remember: When the alternator reaches it's current limit, the voltage regulator rolls back the voltage to keep the current flow in check.
"Something" is using a lot of power.
We were not running anything at all..we were bringing it home. We lost all voltage and asumed it was the alternator. Found what we thought was a replacement,.worked for a while but now trying to locate the real issue.
I discovered my DUVAC alternator was mis wired when replaced by Nacogdoches Motorhome Services. This only became apparent when I deleted my isolator for a B2B charger when upgrading house batteries to lithium. If the ignition wire on the alternator is getting voltage from the alternator or another source then it will back feed into the dash and all heck will break loose. Mine had the sense and excite terminals bridged with the original sense wire cut and turned into the wire loom. Worked so so until I removed isolator. I have a 98 U270 with a C8.3. Chuck has provided you with various options.
There is a good chance if NAPA sold you the wrong alternator, the one it was replacing very well could have been the wrong type also.
You know what that mean: Something is running on its own.
Example: Recently the Studebaker began sounding its own horn at random times.
I pulled the horn relay and looked inside and found rust making an electric connection so I replaced the horn relay.
Horn went sounded off later. We measured 5V on the signal wire to the horn, normally an open ground. I think I know why it's conducting.
One of those cheap over the battery cable ammeters may be enough to get you started in your search. But that electricity is going some where.
And yeah, go for a Leece Neville Duvac or a BIRD* relay.
Any time you run electricity it's a safe guess that you'll lose 0.7V due to the Diode being in circuit.
*Bi Directional Relay Disconnect. Two relays with voltage sensing electronics.
Many good replies here, but reading through the original post I don't see that the alternator is necessarily even working...
Agree that the condition of the alternator is unknown. The way it was installed, with incorrect wiring connected to the "I" terminal, may have immediately damaged the voltage regulator the first time the engine was started. It would require properly wiring the alternator, and then testing it, to see if it is still alive. But, since the OP hopes to return the Bosch to the store for a refund, it probably doesn't matter if it ever worked.
Alright guys, i ordered the proper alternator, brand new! Got it installed perfectly and we are charging again. But only 11.5 volts according to the guage. Im going to get myself a good tester to figure out exactly what it is and work from there.
I have a tender on the batteries but they are 4 years old and it was sitting in storage when we bought it so i may simply have a bad cell in one of them.
I do have good tight clean cables everywhere and good grounds. Nothing looks out of place with that. I actually even added a good chassis ground wire for the alternator as well.
Any thoughts?
Yes. Are the batteries fully charged? Charging system trouble shooting only works when you're starting with known good batteries that are fully charged. And you've given them 15 minutes to 1/2 hour to recover after engine start.
Referring back to earlier posts in this thread, you should now understand that even if you have installed the "proper alternator" it still will not charge properly unless you have a SENSE wire and a EXCITE wire connected to the appropriate terminals on the alternator. The SENSE wire must be attached either directly or indirectly to the START battery bank. The EXCITE wire must be hot ONLY when ignition switch is in the ON position. Have you verified that both of these wires are connected correctly at both ends?
Also, do not trust the dash voltmeter reading until you have verified it is correct. I recommend checking the charging voltage
directly at the start battery bank using your multimeter.
Why? By checking at the "end of the line" (the actual batteries) you are also checking the condition of every cable and connection point in-between the alternator and the batteries.
The alternator is hooked up correctly, exactly as shown in the FT drawings, i identified and traced all the wires from the schematics. All of the wires are numbered so its not that tough!
Btw im not the one that wired it wrong or put the wrong alternator on it in the first place. Im just trying to sort it out starting with the correct parts, wired correctly. One step at a time.
The batteries have been on a tender, i do not know the condition of them yet. They started the coach just fine but they are 4 years old. One could have a dead cell, dropping the voltage.
My volt meter has short leads so im going to get one a little easier to use.
Thanks.
Now that you have the proper alternator and it is hooked up properly here is a couple of things to start/continue your troubleshooting.
If the wiring is original check the sense wire where it terminates on the little breaker on the Isolator board. Replace the breaker if it has bad resistance or just replace it as they are cheap and are located in a bad location. This isolator board could have been mounted in a better place as FT engineering failed in this location.
While there look to see where the other wire going to the breaker is terminated to get power. Some have moved this wire to a battery post rather than hooked in to where the dash air condenser fan is hooked up. This location can send a bad voltage reading if the condenser fan is shorted internally.
Check the isolator to see if one of the diodes have failed. If bad there are several options for replacement/upgrades.
Verify the dash voltage meter is somewhere close so you can see if something is going downhill while you are driving. Those gages are notorious for being off.
This is thoughts of this morning
Mike
This one is easier than you might think and only requires time. Disconnect the batteries. Wait three hours. Measure and record the voltage(s). Come back 24 hours later and measure again, you should have the same readings or higher. Why higher? Because it takes a lead acid battery 24 hours for the final "charging" chemical reaction to complete after charging voltage is removed. Lower voltage means an internal short circuit and time for new batteries.
Easiest place to check voltage is at the diode-based battery isolator.
Wires are numbered, but center lug is from the alternator B+ terminal.
The two outer lugs are to the respective chassis and house battery banks.
Check voltage between good clean ground and each lug with the engine OFF.
Then, start the engine and bump idle speed up to 1,100 RPM and recheck.
A bad battery isolator can give the same symptoms as a bad alternator.
The "proper" alternator may have different voltage regulators, some externally adjustable (desirable), some internally adjustable (most popular), some non-adjustable fixed voltage (not recommended) .
What is the output voltage from the "proper" alternator, and keep in mind the voltage from isolator to battery banks will be lower than alternator voltage.
Measure at isolator, batteries, alternator, as meters at dash may be inaccurately lower due to voltage drop caused by other devices on the wire feeding dash meter.
Talked to WP,will check his coach when the rain stops here,only an hour from me.
Alrighty then, more confused than was to start with.
New correct alternator, wired according to the FT wiring diagram.
Engine running at 1100rmp
Positive stud on the alternator 2.27v
Nothing measurable on the 2 smaller ones 1-2 volts
Isolator
Left 13.48
Middle 2.28
Right 12.66
Batteries each show 12.67 volts (have been on a tender and turned it off for 30 minutes before starting)
Solenoid small terminals both read 31.9 volts
Gage reads 11volts (wither meter 11.97)
And I don't see a little breaker that the sense wire goes to.
The 2 coming off the Solenoid are faded and hard to read.
Good news Napa refunded the $500 on the non duvac alternator.
And thank you all again for taking your time to help me.
And I have an belt tensioner idler bearing going out beside the alternator.
Sounds like the aliens have landed. Spray lube quieted it for about 30 seconds.
2.27v on the alternator positive output post means your alternator is not turning on. If, with engine running, you are NOT measuring 12+ volts on the alternator SENSE and EXCITE terminals, then the alternator will not turn on. You need to find the problem with those two wires, and correct it.
The isolator readings look OK. The center post should read the same voltage as the alternator Positive output post. The outer lugs should read the same voltage as the battery banks.
I don't know what "solenoid" you are looking at. There is nothing on your coach that has 31.9 volts DC power. ?
If you don't see the circuit breaker that the SENSE wire is supposed to connect to, then where DOES the SENSE wire go?
As for the squealing belt tensioner, see the post linked below:
Part Number Collection (https://www.foreforums.com/index.php?topic=11472.msg129143#msg129143) (Part Number Collection, Reply #64)
You need voltage to both the small posts. One will have voltage all the time and the other should
have voltage with the key turned on. The one with voltage all the time is the sense wire and the
one with the power only with the key one is too power the alternator and the alternator won't
work without power.
Start with checking two things-- the two small wires:
The SENSE wire at the alternator. It should read chassis battery voltage and is the "signal" for how much the alternator needs to output.
It is a small gauge wire and can be broken or connections not clean and tight. No problem running a new one from chassis battery lug of isolator (or any other location on the chassis battery side of the isolator) to the sense terminal of the alternator.
Secondly, the IGN/excite terminal should have 12+ VDC any time the ignition is on. Again plenty of easy places in the engine room to get an "ignition hot" signal.
OK I have nothing at either of the small terminals with the ignition on.
That wire is marked E6 that goes to ignition on the alternator
Temporarily disconnect them at the alternator and isolate so they can't touch ground.
Run new temporary wires as discussed in my post above.
Again, not that difficult to either trace or remove and replace the sense and excite wires.
This is the only solenoid or anything other than the isolator in that area
Trace that wire, must be broken somewhere. It will not charge without ignition power on it, and you must have constant battery voltage on the sense wire or else the alternator won't know how much to charge.
Well i will work that direction. Not gonna happen tonight. Hopefully this rain will stop for a while.
Thanks
Well i will work that direction. Not gonna happen tonight. Hopefully this rain will stop for a while.
Thanks
Rain I can understand. Tomorrow is supposed to be a nice day, Sunday Rain.
Your alternator. The small wires. "I" or ignition is the excitation voltage and strangely enough travels from the ignition switch, through the idiot light on the dashboard to that terminal on the alternator. Your problem could be as simple as a burnt out light bulb.
The other wire aka the sense wire: for all practical purposes is the positive test lead for a high impedance volt meter. That's it. that's all. It's whole raison d'etre is to allow for losses between the source and the load, the alternator and the battery. The alternator's voltage regulator measures the voltage at the load using that wire and adjusts the alternator output voltage accordingly.
I agree with Brett: make a wire with alligator clips and go right to the battery just to prove out the new alternator. The sense wire can remain connected but the "I" or "E" wire will drain the battery if left connected.
I believe that is the BOOST solenoid. It is not a solenoid brand that I recognize, but does look to be continuous duty rated. I flipped your photo over so we can read the white label on one of the big red battery cables. Cable ID number is B14, which matches ID number on the cables running from isolator to solenoid in the wiring diagram I posted in Reply #8. Note that there are
two big battery cables attached to each of the large posts on the boost solenoid. The clean(er) red cables go from the solenoid to the battery isolator. The dirty cables go from the solenoid to the respective battery banks.
See the diagram below (with some details added in red).
Before the rain started again this morning. I started tracing wires and studying diagrams. I have 6am ignition excite fuse or relay in the main 12 compartment right beside the door.
#35 on the schematic. No continuity! I believe is the term. So its blown! I am not familiar with this type of set up.
Are they fuses?
Do you just replace them?
Do i need to order myself an assortment?
Do i have to disconnect this whole bar to get that one out? Looks like a lot of work to just change a fuse.
How does this work?
The items you are looking at on that panel are circuit breakers, not fuses. They should all be Type 1 "auto resetting" circuit breakers. A auto resetting breaker will open if there is a short or excessive current flow in the circuit, but it should reset (close) as soon as power is removed from the circuit. If the circuit breaker is "open" (shows no continuity between the posts) when there is no power on the circuit, then it may have failed. In that case you would need to replace it. See link below for more info:
Bussman Automotive Circuit Breakers - Wiring Products (https://wiringproducts.com/collections/bussmann-short-stop-circuit-breakers)
I was wrong, it has continuity when the key is on. Just keep thinking it has to be a blown fuse or something, i cant find anything loose worn or tattered in the electrical work. Cant image both of these being dead. I will definitely try new wires to see if it will turn the alternator on but i want to find out where its broken or loose
Having a tone tracer will make it easier to trace the wires. Could the old alternator been OK and the
problem was no ignition current and no voltage to the sense post.
The old alternator was not a duvac. Just a regular 160 amp.
If your coach still has the diode-based battery isolator, you MUST use a DUVAC as that external sense wire signals the alternator to put out enough volts to compensate for the voltage loss across the isolator. The goal is to get the correct charge voltage to the chassis battery (which also gets the correct charge voltage to the house batteries assuming the system is working properly.
As Peter suggests, a tone tracer would be handy for checking the wires. You can buy one for not much $ at the big box stores. Since your coach has had so many alternator swaps, almost any kind of damage to the OEM wires is conceivable. Perhaps the wires you have connected to your alternator are not connected to anything on the other end. Stranger things have happened...
I wouldn't be too resistant to the idea of running a new set of EXCITE and SENSE wires. It might be the quickest solution.
YUP!
Yes, long term, find the other end of both excite and sense, since both are HOT (sense hot all the time, excite ignition hot).
So many comments to try and sort through on here. Im working offy phone. So let me clarify.
Excite wire needs to be hot with ignition on only
Sense wire should be hot all the time?
Sense is E86 and goes to the remote stop button after the cir breaker on isolator panel (there is not one there that i can see)
Excite wire is E6 and goes to circ beaker 35 in the main panel. (It has got to be broke somewhere in between.
You can do what Chuck suggested and run two new wires and get it going and then you have
lots of time to trace out the old wires and use them later if you want to. Yes to your last question.
Yes that is correct
Looking at the bottom center portion of schematic B-2126 linked below, I would disagree with this statement. According to the schematic, the SENSE wire is E59 (white) and it goes from the alternator to a 15A circuit breaker on the isolator panel, after which it goes to the START battery post on the isolator. This same E59 wire is also shown in the small schematic I posted in Reply #46.
https://www.foreforums.com/index.php?action=media;sa=media;in=3297
I dont have a circuit breaker in the isolator panel. Where is it and what does it look like? There is nothing there but the isolator, the solenoid and the batteries there. I saw all the pix in rhe other alternator posts. My doesn't look like that.
Is it one of these under the bed?
Is it one of these!
It could be one of those in the photo.
You are looking for a circuit breaker
exactly like the ones on that big panel near your entry door. In your photo, there are 2 of them mounted below the silver solenoid (which might be your AUX START solenoid).
I don't know what the two items are in the right side of the photo.
You need to pull back the split wire protector on all those wires and see if you can find any wiring ID labels. If you find labels, compare the ID numbers to your wiring schematic. That's the best way to figure out what you are looking at on your coach.
I have no power to the remote start either. But cant find a clear answer if that supposed to be ignition hot or always hot. I read ten pages in here of Yes and No. With no definitive answer.
Key on only time there is power at the remote start. If the remote start and stop push switches are original I would replace both. Mine shorted out and the stop button killed the Ignition while running on my coach.
Larry
If The E86 wire is supposed be hot all the time as the sense wire, it also goes right to the remote start button which is only ignition hot?
I'm gonna replace with new breakers, relays and remote start Solenoid. All of it looks corroded and crusty.
I can read all the numbers clearly if anyone know what they are.
Still don't understand why the ignition exciter wire is not getting power.
I will have post a picture separately from my phone.
This is all needs worked over.
The one on the left is open or the far left leg! The rest of that bar is hot. Id replace all of it if i just knew what everything is and where it is.
The bar supplies power the the circuit breaker for the 2 wires on the left. Should be auto reset but am not sure. Get a number off it and buy one.
Yes sir, i get that, the bar gets power from the far right side. The one on the left is not resetting as best i can tell. There are no numbers left on them. Looking at the schematic i believe they are 15 amp.
A looking at the pic. shown the breaker on the left should be 15amps and the one on the right should be 20amp. auto reset.
@ Chuck. The stuff on the right hand panel is due to this coach is a 270.
Mike
SO, the left-hand circuit breaker in the photo is open (tripped) and will not reset.
What is the odds one of those two wires on the "load" (non-powered) post of the left-hand circuit breaker might be the SENSE wire?
Any bets?
Im gonna replace both and probably those two relays as well. Trying to find the numbers for that remote start solenoid and the switches for it.
All of those contacts are sketchy
You don't have a separate "remote start solenoid" on your coach.
You DO have a AUX START solenoid (or on some model years a AUX START relay), and you have a BOOST solenoid. (There is also a STARTER solenoid bolted to the starter, but that's another subject)
At the front end of the coach you have a IGNITION solenoid (either one or two, depending on model year).
If you are talking about replacing the round silver solenoid in your photo, the model usually recommended on the Forum is a Cole Hersee 24213. It can be used as a AUX START solenoid, and as a BOOST solenoid, and as a IGNITION solenoid. Works very well in all three applications.
Cole Hersee 24213 12V 200A Continuous Solenoid (https://www.amazon.com/dp/B005K2429I?ie=UTF8&tag=foreforums-20)
Somewhere around %100
Doing that may fix some of the dash A/C problems. One of those is for the condenser fan the other is for the compressor clutch.
Mike
The "Remote Start Switch" operates the same starter solenoid(s) as does the ignition switch.
Well I cleaned wires and tightened a few things up.
Disconnected the ignition wire from the alternator and got 11.8 volts with the ignition on.
When I reconnect it and put the tester on it (with an aligater clip), I have nothing!
Ran pigtail from the Isolator chassis side to the other post (Sence wire) and still only had basically nothing for volts at the center lug.
All of a sudden the idler bearing squeak got so bad I could not hear my cussing.
So I'm gonna replace that now and probably put on a new belt for good measure.
Have the breaker ordered that's stuck open and idler ordered.
Will work on it again when I get that fixed.
Belt shouldn't be too hard to find.
Your weird voltage readings may be due to a problem with your multimeter, or a problem with your test leads (alligator clip).
Try to always use a Gates Green Stripe belt if possible. They are the best quality.
https://assets.gates.com/content/dam/products/gates/power-transmission/micro-v-belts/automotive/heavy-duty/heavy-duty-sell-sheet-fleetrunner-belts.pdf
Not arguing with you what so ever just trying to figure it out too.
I have good voltage with the same alligator clip with the ign wire disconnected and ignition on!
Not sure why i would have nothing, same clip, same wire and same meter with the wire attached.
Meter shows 13.4 volts at each battery every time.
Meter works fine. Wire and clips are fine. Alternator not working worth a dern.
And i did order a green line belt. ty
And believe it or not my coach is in very good condition, wiring isnt butchered or chopped up, very little rust, Just have something weird going on. But i do appreciate your assistance.
Thank you,
I can think of no logical explanation for the test results you are reporting.
You have not yet mentioned the make and model of your new alternator. Is it a Leece Neville? If so, what model number?
Think your coach sat near water and moisture in it's home state,those screws on the metal panel holding the solenoid look
mighty rusty,make sure none of the components are grounded thru that metal plate,if so that may be a problem,you also have
that old insulation falling apart on the compartment walls,most of us with the older coaches have redone that,when you get a
chance come look at mine.
Yes sir it is a new leese neville 2824LC i believe. The one one of the guys here sent me then links to. It didnt have the original one on the coach when i bought it.
And yes i know the insulation needs to be replaced. Its the original. I am actually looking at using roxul on it and the generator compartment, But i have only owned it three weeks..and it came from atlanta by way or florida around 15 years ago. There is very little rust under the bus. Those plates are actually about the worst i have seen anywhere so far.
One thing at a time, sir, one thing at a time.
"What we have here, is a failure to communicate."
Well, you've been bitten by the High Impedance trap.
With the wire disconnected you measured leakage voltage on the wire. When you reconnected the wire, the electrons for that leakage voltage were bled to ground through the exciting circuit. Your wire is "patent" but somewhere along the way, between source and load, there is a very high resistance connection.
Remember: Voltage is electrical pressure, so electron need move, only push.
Current is the flow of electrons, each screaming "I'm Freeeeeee!"
It used to be that the cheap Radio Shack multi meter put enough of a load on the circuit being tested that this trap didn't really exist. But even the $8 Harbor Freight multi-meter has a high impedance input and can measure voltage without causing any electrons to flow.
OK, that is the correct type/size alternator for your coach. I just asked because I'm trying to eliminate all possible reasons why this setup is not working. You have the right alternator. You have hooked up new EXCITE and SENSE wires, and you get the correct voltage readings (SENSE hot all the time, EXCITE hot only with ignition switch ON) from both wires when the wires are
not connected to the alternator.
But then you connect the wires and get no alternator voltage output with engine running. This is (to me) very puzzling.
Old Toolmaker has offered a somewhat esoteric explanation... Go back and check the integrity of your new wiring - make sure everything is tight and secure.
PS: Don't worry about your engine compartment insulation. My engine compartment has looked
worse than yours for the 10 years we've owned our coach. It's on my list of things to do, but never makes it to the top. And yet I sleep just fine at night. 8)
I have parts ordered to fix a couple other things that are in the way of finishing this.
1) a new tensioner and belt. (The bearing started roaring on me mid alternator)
I ordered a new tensioner and a set of bearings for the old one (to rebuild as an extra)
2) That one breaker on the left against the forward firewall is stuck OPEN! and all those contacts are crusty. I ordered new breakers and relays to replace all that. Then I will re-address this issue and give yall feedback.
Thanks so much,
The only word that I expected to be looked up in any good dictionary was "patent" and that I borrowed for its medical definition.
Old T,
No offense intended. It's not yer words...it's the electrical theory. Sometimes I have to think about technical stuff for a while until the fog clears...
So I connect one end of a wire to a known good voltage source (say 12 volts for example).
Then I check the other (unconnected) end of the wire with a multimeter and read the same voltage (12 volts).
Then I connect the (unconnected) end of the wire to a terminal on some electrical device (that is not turned on or operating).
Now, when I check the voltage on the end of the wire that I just connected, I find no (or very low) voltage.
You offer as an explanation: "...somewhere along the way, between source and load, there is a very high resistance connection".
I'm trying to imagine what would constitute a "very high resistance connection". Over the years, I've wired up probably hundreds of 12 volt electrical devices in various vehicles. Due to necessity, haste, or frugality, I've sometimes used junky old lengths of wire cobbled together with multiple amateur crimped connectors and twisted together splices covered with cheap electrical tape. In spite of that, the devices have (almost) always powered up and worked...at least for a limited time.
In the case of Wpduffey and his recalcitrant alternator, I am assuming that his newly installed EXCITE wire is just a single length of wire with some sort of connector on each end. IF this assumption is correct, I have a hard time understanding how your explanation would apply. But as I've said around here many times, I'm just an English major so electrical theory appears, to me, to be equal parts magic and science.
First of all I'm thinking of a resistance on the MegaOhms scale.
You wrote "I am assuming that his newly installed EXCITE wire is just a single length of wire with some sort of connector on each end."
And I answer: With a self resetting circuit breaker in between whose contacts may have grown resistive over the years.
Second a corroded connection easily fits the bill, although in the past some pencil "lead" on a piece of paper has worked well as a megaohm resister for a grid leak. That's the charge that builds on on the grid of a vacuum tube unless given some place to go.
Dirt on an open connection is enough to pass enough electrons to fool a modern high impedance voltmeter.* I myself got bit last summer and threw myself on my soldering iron, confessed my transgression, and accepted the abuse directed my way after wasting a day chasing electrical færies.
*Touching the probe with a finger tip is enough to drain off the leakage voltage. Most of the time.
Guys i cant really do anything with lt right now until i get my parts in but i do appreciate yall thinking about it. Let me state a couple clear facts here to make sure we are reading the same music.
1) i have a brand new leece neville 2824 alternator (hooked up correctly and grounded well)
2) the E6 ignion wire from the ignition is hot when on (13+ volts) when tested loose. When i bolt said wire to alternator and test it, i have no voltage.
Oh and i did check it at the breaker by the front door as well. A good solid 13+ volts with ley on and zero when off.
3) existing since wire E59-E86 was not hot at the alternator when connected. I did find an open breaker that i showed a picture of earlier. I have an assortment of them ordered and will clean all that up. I did run a good solid hot wire (with good copper strong alligator clips) from the alternator to the chassis hot terminal on the isolator as brett suggested to try and test the alternator. Along with the already ignition hot wire hooked up on the alternator. Zero voltage at the center terminal on isolator when running.
4) i was mistaken earlier on when i said i had a 2-3 volts at the middle isolator terminal and the alternator when running. It was slowing millivolts and it was dark and rainy. I actually have nothing there. Running or dead.
5) both batteries show a solid 12.67 volts.
6) both outside isolator terminals show 12-13 volts. (Which they should be same as batteries)
7) dash guage was reading about 11 volts. Testing the wires on the back with meter 11.97 volts
Any other specific questions please ask them. Thanks
Please update us after replacing the parts mentioned.
Thanks.
I absolutely will follow up. And im learning a lot along the way. Its a PITA way to learn but knowledge is knowledge!
I made up a test light using a halogen headlight bulb as I have had good readings with a voltmeter
and an ordinary test light but wire wouldn't carry any current. Also just because the alternator is new
doesn't mean it works
Old T. is correct, if this wire had 12v measured when disconnected at the Alternator end and zero volts when connected, there would have to be a very high resistance either in series, or at its source, or there would be a tripped breaker, blown fuse or the smoke would be released from somewhere. Or.... the wire would become a heating element!
While disconnected, try using a 12v test lamp instead of a meter.
Just to give yall a quick update got all my parts.
2 of the belts were incorrect off that parts list.
So it's gonna be a minute before I put it back together.
Look like 97 and 98 were the same belts but the ac and alt are definitely short. Looks like I'm gonna need that 63.5"belt.
Thanks,
Good evening FT fans and mechanics.
First and foremost thanks for all your help.
Have correct alternator and a full new set of belts and idler/tensioners
I now have 12.99 volts at the middle terminal on the isolator.
Here is what I found.
The 15 amp breaker under the bed is the one that most coaches have in the chassis batter compartment was stuck open. (NO SENCE WIRE) rebuilt that board and replaced both breakers and relays, cleaned everything up (boom voltage)
The E6 wire (ignition hot) has voltage until you hook it to the alternator. No idea why or what to do with it now.
I ran a temp ignition hot (as wolf suggested) from the remote start switch (boom voltage)
So long story short the coach had no sense or ignition excite voltage (so it can happen) not sure how long its been that way, I do know that it's had 6 alternators including this one.
YeeHaw!
Now any recommendations what to do with the E6 wire and where do yall recommend I run another permanent ignition wire from?
I have 2" roxul board on the way to finish cleaning up the engine compartment. Also gonna order a couple nice led under hood lamps. I'd appreciate if yall have an opinion there too.
Quick parts update I wound up using at k080638 alternator belt and a 9470 ac compressor belt. Which it doesn't show for a 1998 U270.
Hate to rain on your parade...but 12.99 volts at the center post on the isolator is still not adequate. Conventional wisdom says you will lose approximately 0.7 volts across the diodes in the the isolator, which means the battery banks will only see about 12.3 volts. This will
not charge your batteries. You want to see 14+ volts on the isolator
battery posts, which means you need at
least 14.8V on the center post.
More investigation is needed.
If it was me, I would run a sense wire
direct from the positive post on a start battery to the alternator. Check if the voltage at the isolator center post improves.
See the post linked below, written by Don (one of the Kool Kids on the Forum). Tells you what voltage AGM battery needs to see for proper charging.
AGM Battery Homework (https://www.foreforums.com/index.php?topic=25597)
Oh i know im not done but At least im charging now, we had nothing before. That in itself is a small victory.
What about the excite wire? Where should i run that from. And what to do with the E6 wire? Tape it up?
Its dang sure easy enough to run another wire frim the battery.
Batteries are old too, could this have any effect here. Im gonna replace them. I just wanted to get it charging.
1. Your excite wire is fine for now. It seems to be working.
2. Tape it up, or put a crimp butt connector on it. You just want to be sure it can't cause a short circuit.
3. The batteries being old is not a factor. You still need to achieve proper charging voltage at the isolator center post.
FYI: that temp excite wire is just a jumper from the remote start to the post via alligator clip. I kust taped of the original to make sure it didnt short out. The since wire was dead because of that breaker being stuck open. Had nothing on it.
Connecting the EXCITE wire at the remote start switch is as good a place as any. Run a permanent wire that is protected as much as possible from chafing and heat. Tie it down with wire clips to keep it from moving around when you are driving down the road.
I like to use the black plastic split wire protector on every wire I run in our coach. It won't stand up to super high temps, so you have to watch where you run it in the engine compartment. But otherwise it does a good job protecting the wiring.
Amazon.com: Alex Tech 10ft-1/4" 10ft-3/8" 10ft-1/2" Split Wire Loom Tubing... (https://www.amazon.com/gp/product/B07TWB5MKD/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1)
The E6 Excite wire needs to be a switched wire (voltage only with ignition on). The old E6 wire needs tape over the end for now.
The voltage sense wire from the alternator needs to go "at least" to the start battery output terminal on the battery isolator. As Chuck wrote, best practice is to run a small wire from the positive terminal on the battery to the sense terminal on the alternator so that the voltage sensing circuit can allow for all line losses and allow the alternator to provide the correct voltage at the battery.
Your "old" batteries would only be a problem if they are "leaky." If you can disconnect your batteries and they measure the same voltage or higher after 24 hours, those batteries aren't a problem in this case.
Sometimes, running a temporary wire or two just to prove that your expensive new alternator really does work is a big step forward if only for peace of mind.
OK fellers, buttoned everything up, wired direct. New ignition wire and fixed the breaker and relays.
At 1000 rpm had 15.06 direct out the back of the alternator
14.99 on center lug of isolator
14.2 on each battery side and just a little less at the batteries themselves.
13.86 at the back of the Gage that's reading about 13.25 is.
Is that good enough? For an old man from Mississippi!
Thanks,
Old? my son is 4 years older than you and I call him the kid.
Thanks so much.