Power drain

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May 16, 2007 | 03:28 PM

baldpuki

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Intermediate

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From: Bountiful Utah

Power drain

My computer is having a bad day and I double posted and then somehow managed to delete both posts on the general site. Probably belongs here anyway.

I have an electrical drain causing my battery to go dead in about 3 days. New battery last week because of this (previous one was an Optima and tested dead). Problem still occuring. I think I read to take the negative cable off and hook up a test light between the cable and negative post and start pulling fuses. I did that and the light stayed on even after pulling all the fuses. What did I do wrong? Where do I start next to track this open circuit? Thanks!!!

May 16, 2007 | 04:02 PM

Team Owner

Joined: Dec 2000

Posts: 21,094

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From: Phila., PA burbs

Do all accessories operate properly? I chased down a battery drain on my car that I had for years. Mine would also go dead after sitting for about three days. It drove me crazy, but I finally realized one of my fans was not working. I tested the fan motor (bad), the relay for that motor (bad) and after replacing both the fan still did not work. Finally I traced the wires for this circuit and found a corroded wire near the fusible links behind the battery. After replacing the wire, the fan worked and the battery drain was gone.

May 16, 2007 | 04:20 PM

bldavis11

Burning Brakes

Joined: Aug 2005

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From: Portsmouth VA

If you have installed an aftermarket car alarm, then it is your most likely problem.

Otherwise,

. What doesn't work?

May 16, 2007 | 04:59 PM

baldpuki

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From: Bountiful Utah

Good questions. As far as I know, most everything works. I haven't had the car that long but I really can't think of other electrical problems other than the dodgy overdrive. Is the test I perfomed the correct test to start narrowing things down? Thanks!

May 16, 2007 | 08:03 PM

CFI-EFI

Race Director

Joined: Sep 2000

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From: The Top of Utah

Quote:

Originally Posted by baldpuki

Is the test I perfomed the correct test to start narrowing things down? Thanks!

Sorta, kinda, yes, and no. It would depend somewhat on what it takes to power your test light. These computer cars with various electronics, radio memories, etc, always have some current draw. You would get more meaningful results with an ammeter. If you eliminate ALL of the current draw, you will have other problems. If you have truly eliminated all of the fused circuits do as TA suggests go after the fusible link circuits, next.

RACE ON!!!

May 16, 2007 | 09:31 PM

ghlkal

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It would be better to use a good VOM (that can handle 10 amp loads) for testing. A small amount of "draw" is normal (IIRC around 50 milliamps). In addition to pulling fuses, there are several connectors "hidden" behind the battery. You'll need to disconnect these also and test as you do.

Gary

May 16, 2007 | 11:30 PM

jfb

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From: Cincinnati, Oh USA

At night, check for underhood lights, vanity mirror lights, door map lights, center console light. Do not leave your key in the ignition because it keeps the theft alarm circuit on. Do you have a radar detector, aftermarket alarm , radio, CB, audio amplifier? Check em. Remove the neg battery cable and connect an ammeter (part of a VOM, voltmeter/ohmeter/milliammeter) from the battery neg terminal to the neg cable. When the courtesy lights time out, switch the ammeter to its lower full scale current so you can read the current. GM says leakage current should not exceed 50 milliamps. My 87 draws 27 ma. Pull the courtesy fuse so you can keep the passenger door open with no lamp current and start pulling fuses one at a time and watch the ammeter and if you find one fuse that drops the current, you can examine that circuit further. Also, remove the nut on the jump start terminal behind the battery and remove the 8 red wires one at a time and watch the ammeter. (not all C4's have this terminal, but you didn't say what year C4 you have) Feel your seat adjust motors, if warm, you may have a defective seat adjust switch. Let us know what you find.