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Alternator HELP!!!

1524 Views 6 Replies 4 Participants Last post by  Derek2010
I have a 1985 CJ7, stright 6

I just bought a new alternator and battery, there is a small drain when the alternator is hooked up (.01 volts per 5 mins) and I tracked it back to the alternator over a long night of tinkering. I have also looked at EVERY diagram on the internet and none of them worked.

When I have the alternator hooked directly up to the battery it charges perfect but the small drain persists, and if hook it up like all the diagrams indicate the alternator doesn't provide enough power. :banghead:

I have even tried another alternator and it also has the same drain, so I am stumped!!!

Can anyone point me in the right direction???
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Does it have a seperate voltage regulator? Also, do you have any items installed that require constant power for memory,like stereo, clock, etc. If so disconnect them and recheck power drain. You did not mention if the battery goes dead over night or not.
A .01 volt drop is meaningless.
Batteries are rated in amp-hours.
Your battery at rest can read 12volts dc +- a volt.
When being charged by your alternator it will charge at greater the 12 volts,, ie: 14 while running.

Your radio clock always draws a tiny bit.

If you knew how to, you could hook your meter up and read the amperage being used.
Don't try this is you have no clue how to.
Magic smoke will appear from your meter.
My jeep is pretty basic.. no raido or clock.

While working on the front axel (2 hours) the battery drained enough to not turn over.

I think I may have pinned the problem.. no diode from the coil to the alternator. Im gonna try it out tomorrow and hopefully it works, otherwise Im guessing the alternator isnt working correctly
The diode wasn't the problem.

I have diconnected the exciter wire from the alternater adn there is still a small drain, so some wire has to be grounded thoughout the jeep.....
You can NARROW that Gremlin down by removing one Fuse at a time, checking, moving to the next and so on, until you discover which circuit it's on, Then check items on that circuit. It will be time consuming and tedious, but it's an option.
Or you could always purchase some test equipment that will trace out Shorts.
Best money I've ever spent. Not to mention the Headaches it's eliminated.
Can I rent the test equipment?

I checked all the fuses already with no luck....
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