Charging issues

Topic: Charging issues (Read 2426 times) previous topic - next topic

Re: Charging issues

Reply #25 – March 02, 2023, 10:51:27 am

Quote from: Dave Larsen – March 02, 2023, 09:56:13 am

...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.

Re: Charging issues

Reply #26 – March 08, 2023, 08:17:55 pm

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?

Re: Charging issues

Reply #27 – March 08, 2023, 08:44:57 pm

Quote from: Wpduffey – March 08, 2023, 08:17:55 pm

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.
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.

Re: Charging issues

Reply #28 – March 08, 2023, 10:24:37 pm

Quote from: Wpduffey – March 08, 2023, 08:17:55 pm

I ordered the proper alternator, brand new! Got it installed perfectly and we are charging again. But only 11.5 volts according to the gauge. Any thoughts?

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.

Re: Charging issues

Reply #29 – March 09, 2023, 12:15:52 am

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.

Re: Charging issues

Reply #30 – March 09, 2023, 06:20:14 am

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

Re: Charging issues

Reply #31 – March 09, 2023, 07:51:15 am

Quote from: Wpduffey – March 09, 2023, 12:15:52 am

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.

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.

Re: Charging issues

Reply #32 – March 09, 2023, 08:22:19 am

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.

Re: Charging issues

Reply #33 – March 09, 2023, 11:32:19 am

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.

Re: Charging issues

Reply #34 – March 09, 2023, 12:50:59 pm

Talked to WP,will check his coach when the rain stops here,only an hour from me.

Re: Charging issues

Reply #35 – March 10, 2023, 06:14:31 pm

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.

Re: Charging issues

Reply #36 – March 10, 2023, 06:37:12 pm

Quote from: Wpduffey – March 10, 2023, 06:14:31 pm

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
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.
And I have an belt tensioner idler bearing going out beside the alternator.

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 (Part Number Collection, Reply #64)

Re: Charging issues

Reply #37 – March 10, 2023, 06:39:52 pm

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.

Re: Charging issues

Reply #38 – March 10, 2023, 06:42:18 pm

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.

Re: Charging issues

Reply #39 – March 10, 2023, 07:08:57 pm

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

Re: Charging issues

Reply #40 – March 10, 2023, 07:23:16 pm

Quote from: Wpduffey – March 10, 2023, 07:08:57 pm

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.

Re: Charging issues

Reply #41 – March 10, 2023, 07:24:56 pm

This is the only solenoid or anything other than the isolator in that area

Re: Charging issues

Reply #42 – March 10, 2023, 07:25:42 pm

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.

Re: Charging issues

Reply #43 – March 10, 2023, 07:34:26 pm

Well i will work that direction. Not gonna happen tonight. Hopefully this rain will stop for a while.
Thanks

Re: Charging issues

Reply #44 – March 10, 2023, 07:41:17 pm

Well i will work that direction. Not gonna happen tonight. Hopefully this rain will stop for a while.
Thanks

Re: Charging issues

Reply #45 – March 10, 2023, 08:44:48 pm

Quote from: Wpduffey – March 10, 2023, 07:41:17 pm

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.

Re: Charging issues

Reply #46 – March 10, 2023, 10:12:18 pm

Quote from: Wpduffey – March 10, 2023, 07:24:56 pm

This is the only solenoid or anything other than the isolator in that area

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).

Re: Charging issues

Reply #47 – March 11, 2023, 02:26:51 pm

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?

Re: Charging issues

Reply #48 – March 11, 2023, 02:55:02 pm

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

Re: Charging issues

Reply #49 – March 11, 2023, 03:24:13 pm

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

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