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-   -   Alternator not charging the battery (Different issue) (https://www.thirdgen.org/forums/electronics/523426-alternator-not-charging-battery.html)

Devryn 04-27-2009 08:15 PM

Alternator not charging the battery (Different issue)
 
4 Attachment(s)
Someone please help me out. Here's the deal. My alternator has not been charging my battery and I couldn't figure out why, so I started tracing cables. Here's what I found.

It APPEARS the positive battery cable is grounded to the car (intentionally or unintentionally). The positive battery cable has TWO cables. The first, of course, is the big thick red cable. The second, is a black cable with a red stripe. It appears to be grounded to the car. ALSO, there is another smaller black cable with a red stripe that is terminated and it runs back toward the car. Not sure what it is. Where it is grounded, it appears that there are other cables that are for power, but what they're supplying, I have no idea, but two of the cables (orange and red) appear to go to a plug on the passenger fender.

Overall picture of the battery tray:
Attachment 432484


Picture of mysterious small black cable with red stripe:
Attachment 432485


Picture of black and red battery cable apparently grounded to the car. Notice the other cables that I think the intent was to provide power to...though I'm not sure:
Attachment 432486


Mysterious plug that an orange and red wire run to:
Attachment 432487

kcallais 04-28-2009 10:45 AM

Re: Alternator not charging the battery (Different issue)
 
Your negative terminal is the only thing that should be grounded. Run the big one to the motor, and a smaller one anywhere where you can find a good ground. The positive terminal should have the large cable running to the starter, along with a smaller one that has some fusible links (3 i think?) on it. Kinda getting ahead of myself so let me slow down.....

First of all....whats the volatge/amperage coming out of the alternator? Remember, for the battery to charge, the alternator has to put out more voltage than the battery has. This is called a positive differential. Your alt should bang out 14-15vdc @ around 40-60amps at idle. Check this first, it will tell you if your alternator is even serviceable or not.

Second.....make sure your charging line from the alternator to the battery is actually connected properly. You can trace the wire from the back of the alternator by hand which would be the most accurate, or if you have access to a multimeter, set one lead on the alternator charging post and tap the other lead on each POSITIVE battery wire until you get continuity. If you never get continuity, then either your charging line is broken or not corrected properly.

As for the pictures....I hate the firewall we have here, so I'll take a look at them when I get to the house and see if I can come up with any more explanations.

Devryn 04-28-2009 11:03 AM

Re: Alternator not charging the battery (Different issue)
 
Tyndall? I was at Sheppard for 4 years (2002-2006). Edit: I was thinking Tinker...oops. It's be awhile. ;) I was AF for 6 years.

I had someone who knows more than I do look at it yesterday, and the "thing" I thought the cable was grounded to was actually plastic, and seems to feed power to a few other wires and isn't actually grounded. I can e-mail ya the pics if you'd like.


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