Having alternator charging issues, had mine replaced @ FOT 2 years ago, but now output is only 2.9V. I have had conversations w/ Red Tractor for diagnosis and it points to the alternator. The isolator and corresponding solenoids look pretty rough, I'm thinking they are original. Going to take the alternator to a local shop for testing and repair if neccessary. Looking @ Victron isolators- I have 2 AGM Deka house batteries and 2 start batteries. I have @ '93 280 with the 8.3. My boost solenoid appears to be bad so I ordered a new one. The whole isolator area looks weathered and worn so it's overdue for replacement components. Looking for advice for the isolator replacement- the ones I looked at say 2 batteries? do I need 4 battery isolator? I've been studying the forum to educate myself plus the invaluable help from Red Tractor, but it can be a little overwhelming! TIA
My isolator was a 200 amp isolator and I thought they go by amps and you size them according
to the amps that the alternator put out.
The standard factory isolator setup requires 3 posts on the isolator. One post is for alternator input, and the other two output posts are for your start and house battery banks. Victron is an excellent choice, especially if you pick the Argofet 200A (2 bank) model, which is much more efficient than the diode based isolator originally fitted to your coach.
The "alternator energize input" feature is useful if you ever want to upgrade to a high output Delco alternator.
https://www.victronenergy.com/upload/documents/Datasheet-Argofet-Battery-Isolators-with-alternator-energize-input-EN.pdf
Amazon.com: Victron Energy Argofet Battery Isolators 200-2AC (2 Batteries... (https://www.amazon.com/Victron-Energy-Argofet-200-2-Batteries/dp/B00NT9MTMQ?ie=UTF8&tag=foreforums-20&th=1)
If you are ever considering going to Lithium battery setup now might be a good time to look into a DCtoDC charger to replace the isolator?
Just to put another log in the fire? :o :D
Mine has four posts on it
If you can provide a photo of the rear connection panel on your alternator, or tell us the make and model number, then we can tell you if it is worth your time and money getting it worked on. If it is the incorrect type of alternator for your application, then spending money on it is a waste.
Yes, it has 4 posts, but you will notice that two of the output posts are connected together with a jumper cable. This was the standard Foretravel configuration back in the day, but is no longer necessary with a modern replacement isolator such as the Argofet recommended in my post above.
Numbering left to right in your photo:
Post #1: House battery bank
Post #2: Alternator input
Post #3: Connected to Post #1
Post #4: Start battery bank
LN-A0012824LC
I believe it is the correct alternator. It has served me well for 2 years
Oops, wrong picture before. This is the alternator
Oops, wrong picture before. This is the alternator
OK, that is a good quality alternator, and more importantly it has the correct DUVAC design features. :thumbsup:
Prestolite Products (https://prestolitesuperstore.com/Category/2824LC/OE-Leece-Neville--160-Amp-12-Volt-Brush-Alternator)
It would be very unusual for that alternator to fail after two years. Before pulling it out you should do some trouble shooting to verify it is getting the proper SENSE and EXCITE signals that are required for it to work.
The EXCITE post (marked IGN on the alternator) should be hot (12 volt)
only when the ignition switch is in the ON position.
The alternator post marked SENSE should be hot all the time. The other end of that SENSE wire should be connected to the START battery post on the isolator.
Sense wire matches battery 12.1- batteries are charging, ign wire the same when ign is turned on. I'm open to other test. Checked the 2 posts on the ends when it's running, 2.9v
Dash volt meter shows 10 when running
OK, sense and excite inputs seem satisfactory.
With engine running, what is the voltage on the alternator B+ (positive output post) and on the alternator input post (Post #2 in your photo) on the isolator?
I'm not getting anything
Well, if alternator has a good SENSE connection, and a good EXCITE connection, and is not putting out ANY voltage when turning, then I guess it must be bad. It might be a problem in the voltage regulator...
I've exhausted my ideas, so unless other members have other suggestions then I guess take it to the repair shop and see what they say.
Be sure you tell them this alternator is used with a two battery bank charging system and must be configured as a DUVAC model.
While you are working on the battery/charging system, be sure you clean up the end connectors on ALL of the wires and cables. They should all be shiny clean metal when you put it back together.
The pic of the isolator shows that the isolator has been some kind of hot. Some of your readings could be bleed through the diodes in that isolator. Those wires also need to be checked and cleaned as they look like they have been hot also. Now this rambling leads to the alternator, If it was having to run at full load and is what cooked the isolator then you could have either burnt up a brush and/or it is stuck in the brush holder. In like manner it could have killed a diode in one of the rectifiers. If I was betting on a rectifier with a bad diode I would put my $ on it being the Neg. one. Yes the alternator has a Pos and Neg rectifier. Any good old school shop can check it out and fix your problem. Now a name brand parts store ????
Mike
I found an old school shop not far from me, I have high hopes they'll make it right
Should I replace these or just clean them up? If replace, what are they and where can I get them?
Definitely replace them. They are
auto reset circuit breakers. See if you can read the "size" (15A, 20A, etc) imprinted on the metal case. If not, the B-2126 12 volt wiring diagram for your coach may list the required size. On our '93 U280 they are 15A. They are available at most auto parts stores and online.
Bussman Automotive Circuit Breakers - Wiring Products (https://wiringproducts.com/collections/bussmann-short-stop-circuit-breakers)
Short Stop Circuit Breaker 15A Metal RT Bracket Type 1 12V (BP/CBC-15B-RP):... (https://www.amazon.com/Short-Circuit-Breaker-Bracket-CBC-15B-RP/dp/B00F2NHWRY/ref=sr_1_8?crid=10PU2FR9UWKT4&keywords=Bussmann+15A+type+1+circuit+breaker&qid=1682169068&s=hi&sprefix=bussmann+15a+type+1+circuit+breaker%2Ctools%2C151&sr=1-8)
I see one relay in your photo. I would replace it also. Starting out with everything fresh is good!
Amazon.com: ONLINE LED STORE 12V 40/30 Amp 5-Pin SPDT Bosch Style Electrical... (https://www.amazon.com/ONLINE-LED-STORE-Economical-Installation/dp/B01KVZ2LN2?ie=UTF8&tag=foreforums-20&th=1)
I don't know what solenoid you purchased. The one below is highly recommended by Forum members. Can be used as both AUX START solenoid, and as BOOST solenoid.
Amazon.com: Cole Hersee 24213 12V 200A Continuous Solenoid : Automotive (https://www.amazon.com/Cole-Hersee-24213-Continuous-Solenoid/dp/B005K2429I)
Chuck, thank you for sharing your wisdom with me, that solenoid IS the one I ordered from Amazon, I'll need to order another one and thanks for including the relay. My plan is to get all this replaced including the isolator. I have a new grandbaby about to be born and we're supposed to travel to their house, in the MH, to help with the other previously born offspring. I just want it roadworthy enough to get us to Athens GA about 2 hours away and will address more items as time allows.Your assistance is priceless. Thanks again.
I am going to start by assuming you mean the positive and negative battery posts on the alternator.
2.9V across these two terminals means that you have a high resistance connection and 2.9V is the difference in voltage, which can be thought of as electrical pressure.
Careful probing is the order of the day.
Everything on the negative terminal, post, copper terminal and wire should be 0V to a good ground.
On the positive side you should have battery voltage to ground. I have gone so far at times in the past to run an independent wire from the battery negative terminal to where I can reach it to measure the voltage on that battery wire, when looking for the location of the high resistance connection.
When you find battery voltage load it down with a 12V light bulb and measure again. Used to be you needed a vacuum tube volt meter to get into that kind of trouble but noooo!, all you need is to spend $8 at Harbor Freight for a VOM with high impedance input. The cheap Radio Shack Micronta analog VOM sucked up current at the rate of 20,000 Ohms per volt automatically loading down the circuit under test.
Check the number of pins on the relay before you order new ones. Just pull the wiring connector off and count the pins. "Bosch style" relays come in 4-pin and 5-pin versions.
The link I provided above for the relays is the 5-pin version, and they are not genuine Bosch brand. However, they have worked fine on our coach for many years.
I bought the 10 pack because I also use those type relays in other projects.
So I guess the question is have you done any of this or just ready to remove the alternator?
New isolator?
Cleaned and verified starter cables?
Replaced circuit breakers?
Replaced wire ring lugs on CB?
Verified voltage on sense wire?
Ohmed out all your cables and grounds?
This would be the foundation to a good repair before removing alternator for repair for me
Alternator has been tested good, I'm about to replace my isolator with a Victron Argofet along with cleaning connections and replacing the solenoids, breakers and relays. While at FOT IN '21 @ the GV reunion, they replaced my alternator and also installed a BEP DVSR to my isolator, do I need to attach that to the new Victron isolator? Thanks again for all the great help here!
I am not sure how that is supposed to work, but from what I see, doesn't that take the place of the isolator. If it charges the battery through a relay I would think that it would be keeping the batteries isolated. Like I said, not familiar with that system.
Ron,
That's what I was thinking, I thought it would be redundant to have it. They might have installed it because I was having charging issues.
NO, it takes the place of the old-style diode-based isolator.
So with that, he shouldn't need an isolator. Maybe that is what has been causing the no charging issue.
Wire the Victron Argofet properly and remove the old-generation battery isolator.
Mike said "they replaced my alternator and also installed a BEP DVSR to my isolator".
Not being familiar with a BEP DSVR, would it be tossed along with the old isolator?
Digital Voltage Sensing Relay (DVSR) 12/24V (https://www.bepmarine.com/en/p/710-140A/Digital-Voltage-Sensing-Relay-DVSR)
IMO, either use the ArgoFET isolator, OR, use the BEP DVSR. One or the other - not both.
Thanks Chuck!
Does it go "BEP"? ;D
JUST KIDDING
Only if you pay for the optional "ANNUNCIATOR" feature.
If you go with the Victron Argofet isolator, you may need to turn the voltage output down in the alternator. At the alternator mine is 15.1 one the out put side of the diode isolator it's 14.3-14.4 volts
I am surprised that the sense wire doesn't take care of the automatically, since its job it to provide the correct voltage at the chassis battery bank.
Said another way, if the system does not experience the .7 VDC drop across a diode-based isolator, it should merely communicate the 14.3 VDC to the alternator.
It may, that's the way it's SUPPOSED to work.
Yes, if it doesn't, a good idea to verify that the sense wire connections are clean and tight. A little resistance can cause the alternator end of the sense wire to read lower than actual and lead to high voltage output.
just wanted to follow up with the replacement of isolator and alternator issues. Long story short, replaced isolator with the Victron Argofet, replaced old boost and starter solenoids, replaced old, worn resettable breakers and relay. Finally found the problem wire for the alternator- ignition sense wire was hooked to the wrong wire, once that was identified, everything is working. I deeply appreciate all who gave me advice and help. It was a great feeling to get my batteries charging again. Special shoutout to Red Tractor who took many frustrated phone calls from me.
FYI the SENSE terminal is connected directly to the chassis battery side of the battery isolator.
The IGN terminal is connected to some "only hot when ignition on" source.
They provide two very different but necessary functions.
I seem to remember reading that FOT installs a BEP DVSR to function as a Trik-L-Start to charge the chassis battery while on shore power.
The BEP DVSR, like the Xantrex Echo Charger is one of the "smart thief" type devices to charge the chassis battery from the house battery bank when the house bank is being charged (voltage of 13.2 VDC or higher).
It is a reasonable alternative to a stand alone low amp smart charger.