Can you help me diagnose my charging system malfunction please?

Tiny
SOLARNATE
  • MEMBER
  • 1991 PLYMOUTH ACCLAIM
  • 135,000 MILES
The alternator and battery test good, but the battery receives NO charge from the alternator. I replaced the ECM with a salvaged one, the results were the same so I switched the old one back.I've identified a short circuit in fuse 2. All of the wires under the dash and in the engine compartment look good, grounds and connections appear tight with little corrosion. I've been doing continuity tests with a haines manual, everything looks good so far. Any suggestions, or do you know where I can find a more detailed wiring diagram?
Saturday, April 28th, 2012 AT 6:14 PM

8 Replies

Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
Do you have 12 volts to the back of the alternator? If you have identified a short circuit in fuse 2 and have tested the wires and connections with a continuity test

Roy
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Saturday, April 28th, 2012 AT 6:17 PM
Tiny
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I think my voltage at the back of the alternator was a little higher, I'll check again tomorrow. I'm also planning on checking the fusible links and running more continuity tests.
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Sunday, April 29th, 2012 AT 3:47 AM
Tiny
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  • 4 POSTS
I found 12.4 Volts on one of the connections at the back of the alternator (to the - terminal), the battery voltage was 12.75 at the time.
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Sunday, April 29th, 2012 AT 7:58 PM
Tiny
MAURICIOTAN
  • MEMBER
  • 1 POST
Here is the alternator wiring diagrams. Check out the images (Below). Please let us know what happens.
Image (Click to make bigger)
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Tuesday, May 8th, 2012 AT 11:01 AM
Tiny
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  • 4 POSTS
Thank you I found the fusible link was bad.
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Tuesday, May 8th, 2012 AT 2:37 PM
Tiny
WRENCHTECH
  • MECHANIC
  • 20,761 POSTS
Thanks for letting us know, we are here to help, please use 2CarPros anytime.
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Tuesday, May 8th, 2012 AT 2:58 PM
Tiny
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  • MEMBER
  • 4 POSTS
I don't really know who I'm talking to. All I know is that my questions have not been answered, and I'm over trying to find answers on this forum or any of the other ones I've tried. Everyone wants you to pay money to find out the least little detail. "Take it to an expert mechanic" thanks, whoever wrote that. I thought I was speaking with a mechanic.

I tried asking nicely for help 2 weeks ago. I apologize if I come off like a real jerk here, but what kind of response was that? I asked for assistance or diagrams, I was given crappy advise, am I wrong? Again, my apologies for being annoyed, if anyone has any good advise I'm willing to try it. If not, thanks anyway, I will get this handled myself without having to buy a new vehicle.
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Wednesday, May 9th, 2012 AT 1:20 PM
Tiny
WRENCHTECH
  • MECHANIC
  • 20,761 POSTS
Anybody is allowed to post here but if it doesn't have the pink background on the answer, then it wasn't posted by one of the regular experts here. We do this voluntarily on our own time.

The voltage regulator for your car is built into the Engine Control Module. Wilt a voltmeter attached across the battery to read voltage, locate the dark green wire at the alternator and back probe it with a jumper wire. With the engine idling, momentarily ground it and see if the voltage jumps up. If so, you need a new computer.
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Wednesday, May 9th, 2012 AT 1:31 PM

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