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Author Topic:   Battery Drain
CraigStephens
Journeyman

Posts: 14
From: Atlanta Area
Registered: Jan 2006

posted 05-01-2006 04:25 AM     Click Here to See the Profile for CraigStephens   Click Here to Email CraigStephens     Edit/Delete Message   Reply w/Quote
I have just about finished the restoration on my '68GT Convert. After getting the electrical system hooked up, I find that my battery drains down overnight. I tried pulling all of the fuses out of the box, and it holds a charge, but so far any of the fuses I put back in causes a slow drain of the battery.

Anyone have a suggestion on the next step to take in order to find the electrical gremlin? Most of the wiring has been replaced. I had the guy in Texas go over the main underdash harness, so I think that is in good shape.

Craig

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exlocal
Gearhead

Posts: 1170
From: hacienda hts., CA, USA
Registered: Dec 2004

posted 05-01-2006 09:01 AM     Click Here to See the Profile for exlocal     Edit/Delete Message   Reply w/Quote
Try putting in the fuses one at a time with a voltmeter on the battery to see if there is a large drain when installing the fuses. If not, try installing just half of the fuses and see if the battery drains overnight. When you find the group of fuses that drains the battery, split that in half again. You will eventually find the circuit that is draining the battery. Good luck.

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reliving youth

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Mark Ugrich
Gearhead

Posts: 233
From: Waukesha, Wisconsin,U.S.A.
Registered: Jan 2006

posted 05-01-2006 09:55 AM     Click Here to See the Profile for Mark Ugrich   Click Here to Email Mark Ugrich     Edit/Delete Message   Reply w/Quote
quote:
Originally posted by exlocal:
Try putting in the fuses one at a time with a voltmeter on the battery to see if there is a large drain when installing the fuses. If not, try installing just half of the fuses and see if the battery drains overnight. When you find the group of fuses that drains the battery, split that in half again. You will eventually find the circuit that is draining the battery. Good luck.


Sounds like a good plan to me!Using an ammeter would be more accurate in finding a drain on the battery.

[This message has been edited by Mark Ugrich (edited 05-01-2006).]

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CraigStephens
Journeyman

Posts: 14
From: Atlanta Area
Registered: Jan 2006

posted 05-01-2006 10:22 AM     Click Here to See the Profile for CraigStephens   Click Here to Email CraigStephens     Edit/Delete Message   Reply w/Quote
I will try that. So far the first two fuses I put back in each caused a slow drain. I will continue to work my way through all of them.

Craig

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Scott H
Gearhead

Posts: 1092
From: Chicago area
Registered: Mar 2005

posted 05-01-2006 11:40 AM     Click Here to See the Profile for Scott H   Click Here to Email Scott H     Edit/Delete Message   Reply w/Quote
Are you sure the battery isn't in backwards? LOL

This doesn't have an alarm on it does it? Or the radio hooked up directly to the battery?

If you've got a drain with the first two fuses, do you still have a drain with NO fuses? could be the drain is being caused before the fuse box, not after. It would be strange that you would have two separate circuits (the two fuses you tried) causing a drain.

[This message has been edited by Scott H (edited 05-01-2006).]

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Tom G
Gearhead

Posts: 922
From: Bethlehem, Pa USA
Registered: Nov 2001

posted 05-01-2006 08:12 PM     Click Here to See the Profile for Tom G   Click Here to Email Tom G     Edit/Delete Message   Reply w/Quote
What is battery voltage after charging and car is off and no fuses 13.5 or better? Are brake lite on or possible emergency flasher? If you can narrow down the fuse that is the culprit> we can help find a cause. Does car have a cigar lighter installed? Aftermarket radio with a memory wire or power antenna connection? Bad rotary switch on dome lite control can cause a drain also.

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[This message has been edited by Tom G (edited 05-01-2006).]

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CraigStephens
Journeyman

Posts: 14
From: Atlanta Area
Registered: Jan 2006

posted 05-01-2006 09:58 PM     Click Here to See the Profile for CraigStephens   Click Here to Email CraigStephens     Edit/Delete Message   Reply w/Quote
I have been checking fuses. So far each one I check causes a drain on the battery. There aren't any drain items except the clock installed in the car. The drain is occuring with the ignition switch off. It is somewhere past the fuse block. With all of the fuses out, it holds it's charge. I can measure the voltage across the battery posts, but not load.

Yes, the battery is in the correct way. :-)

Craig

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CraigStephens
Journeyman

Posts: 14
From: Atlanta Area
Registered: Jan 2006

posted 05-02-2006 05:58 AM     Click Here to See the Profile for CraigStephens   Click Here to Email CraigStephens     Edit/Delete Message   Reply w/Quote
Is it possible for the fuse block to be bad?

Craig

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Mark Ugrich
Gearhead

Posts: 233
From: Waukesha, Wisconsin,U.S.A.
Registered: Jan 2006

posted 05-02-2006 10:38 PM     Click Here to See the Profile for Mark Ugrich   Click Here to Email Mark Ugrich     Edit/Delete Message   Reply w/Quote
It would be unusual for the fuse block to be defective.Try this, disconnect the positive battery cable. connect an ammeter with one lead one the battery post and the other on the battery cable.put all the fuses back in and check to see how many amps are being drawn.Now remove the fuses one at a time until there is no amp reading on the meter. the fuse that stops the drain is the circuit you need to investigate.
If none of the fuses stop the drain, disconnect the wiring to the alternator.It is possible for a bad diode in the alternator to drain the battery also.

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CraigStephens
Journeyman

Posts: 14
From: Atlanta Area
Registered: Jan 2006

posted 05-03-2006 02:46 PM     Click Here to See the Profile for CraigStephens   Click Here to Email CraigStephens     Edit/Delete Message   Reply w/Quote
Thanks,

I will try that.

Craig

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CraigStephens
Journeyman

Posts: 14
From: Atlanta Area
Registered: Jan 2006

posted 05-13-2006 09:11 AM     Click Here to See the Profile for CraigStephens   Click Here to Email CraigStephens     Edit/Delete Message   Reply w/Quote
I found part of the problem. I was using an aftermarket set of battery wires. The positive lead was 4 guage and I liked it being heavier than the original. Unfortunately it was longer also, and apparently it rubbed when the engine was running. A hole ended up being worn through the insulation, and it was touching the back of the alternator. Why this didn't cause a huge short I am not sure, but it did cause a definite drain. That masked whatever else is wrong to some extent. Now it is time to go back and check each fuse circuit for the problem.

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Mark Ugrich
Gearhead

Posts: 233
From: Waukesha, Wisconsin,U.S.A.
Registered: Jan 2006

posted 05-13-2006 03:44 PM     Click Here to See the Profile for Mark Ugrich   Click Here to Email Mark Ugrich     Edit/Delete Message   Reply w/Quote
Man, were you lucky! That kind of stuff can cause a fire. A drain is certainly the lesser of two evils.

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