Oh no. Another one with a problem with the 12V alternator 1 (driverside)

[Der Dicke]

Hello,

please don't shoot me, but I have a problem with the alternator 1 (driver side).
I find a lot of good threads to check, but I could not solve my problem. Possibly overlooked.
Alternator 2 is charging, #1 is not.
Before the engine was changed (timingchain crack), it works.

The Gen1 lamp did not glow with ignition on. Gen2 glow and is off with engine running.
I checked the lamp and fitting- it's ok.

The voltage on the regulator Terminal 1 and Terminal 2 is correct. I found here a good thread about it.
If I short circuit the Terminal 1 (wire form indicator lamp) the Gen1-lamp glow.
So the connection from the Gen1-lamp to the alternator is correct. Or?

I connect a 4W bulb (as indicator lamp) from Battery(+) to the Terminal 1 but it does not light up either.
I connect a second ground on the alternator 1. Doesn't help.

Both alternator works, if the alternator is built-in on the passenger side!

Any guess? I hope you understand my (german-) english.

The last way is to convert to 12V, but the more i read the more i like the 24V system.

greetings from germany,
richard

 

[Tow4]

Make sure the ground is connected to the isolated ground terminal and not the case ground. Is the ground wire damaged, is it connected to the front battery? I know you said the alternator works if you put it on the passenger side, if that is true, then there is no ground to the alternator on the driver side. That is why the light is not coming on.

Did you do this test?

Testing the Alternator on the Vehicle

A lot of people have problems with the CUCV charging system and I have been posting to individual threads in an effort to help people with alternator charging problems. Since I find myself posting the same thing over and over, I decided to put together a short thread on how to test the...

www.steelsoldiers.com

 

[Der Dicke]

Yes, I have seen the thread and it is very good described. I have done it in that way.
Because of it, I am a little bit confused and it must be the alternator. But if I swap them, the error is still on the same side.
The ground to the alternator 1 should be ok. I short circuit the Terminal 1 (wire form indicator lamp) to the alternator case and the lamp is glowing.

 

[Tow4]

Yes, I have seen the thread and it is very good described. I have done it in that way.
Because of it, I am a little bit confused and it must be the alternator. But if I swap them, the error is still on the same side.
The ground to the alternator 1 should be ok. I short circuit the Terminal 1 (wire form indicator lamp) to the alternator case and the lamp is glowing.

You say you swap them from side to side and it works on the passenger side. How can the problem be in the alternator? If you followed my test procedure, The alternator would have worked on the driver's side assuming the B+ and B- wires were connected to the battery.

Forget about the light for a minute. You need to eliminate the truck wiring from the equation so you can determine if the problem is in the alternator or the truck wiring. I would take all of the truck wires off the alternator and run wires from the front battery B+ and B- posts directly to the driver's side alternator B+ and B- terminals. Use jumpers as indicated in my test thread to turn on the regulator using jumpers from the B+ terminal on the alternator.

Or just take the alternator(s) and have them tested. Make sure the person testing them hooks the B- lead from the tester to the B- terminal, not the alternator case, if it is isolated ground.

 

[Der Dicke]

I will do it in that way and will report.
I forgot to tell:
Both alternators were disassembled by a russian (no offense) car-electrician who understand less german and even less english. I think he tested and replaced the parts proper but made a mistake when assembling. I am not for sure he understands the isolated ground, because he played around with a cable from the Bat (+) 24V on the terminal of the 12V alternator (driver side!). Maybe he toasted it.
Thank you ,
richard

 

[Der Dicke]

Problem solved.
The mechanic connects the alternator incorrect!
Additionally he disassembled 3 working alternators (one still in pieces) and I spent many hours looking for the fault.
From german: "I can't eat as much as i might throw up"

Positiv: I found this good forum and learned a lot about the electrics of this car, especially that 24V system.

Thanxs a lot!

 

[Tow4]

Problem solved.
The mechanic connects the alternator incorrect!
Additionally he disassembled 3 working alternators (one still in pieces) and I spent many hours looking for the fault.
From german: "I can't eat as much as i might throw up"
View attachment 827347
Positiv: I found this good forum and learned a lot about the electrics of this car, especially that 24V system.

Thanxs a lot!

Imagine that. Glad you got it figured out.

 

[MarcusOReallyus]

Problem solved.
The mechanic connects the alternator incorrect!

Of course!

That's why we don't recommend taking these vehicles to a regular mechanic, at least not for electrical problems. We've heard lots of horror stories over the years.