parasitic battery drain
Thread Starter
Cruising
Joined: May 2011
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From: sahuarita az
parasitic battery drain
nuked my battery with aserious drain (12 vlts). traced it to the starter harness. disconnected that at the firewall connector and drain disappeared. reconnected it and disconnected starter. drain disappeared again. removed starter and tested the armature, brushes, field coil and solenoid. all good. connected the starter to battery cable to the switch cables and bingo the drain is back. Bad ignition switch?
Le Mans Master
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From: New Hill NC
Most all of the power comes from the starter harness. Naturally it would go away when disconnected. You are most likely barking up the wrong tree. Most drains on that model are bad diodes in the alternator or a bad courtesy light delay module. It would help to know what year though.
Thread Starter
Cruising
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From: sahuarita az
If I had disconnected all terminals at the alternator and drain still persisted would that eliminate the alternator as a cause? Also found that ignition switch would rotate past the locking postion (towards driver) and the drain disappeared. Where is that courtesy light modual?
Le Mans Master
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From: mount holly NC
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Here's a picture,
You can remove the box and connect the two white wires and the lights will go on and off as you open or close the doors or you can get a new delay board from Willcox.
You can remove the box and connect the two white wires and the lights will go on and off as you open or close the doors or you can get a new delay board from Willcox.
Pro
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From: Bryan Texas
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From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
You need to locate which circuit the drain is on.... To do this you'll need a multimeter...
Then one at a time pull a fuse and see which one makes the draw go away.
When you find out the circuit it's on then you can start troubleshooting that circuit.
Post again.
Willcox
Then one at a time pull a fuse and see which one makes the draw go away.
When you find out the circuit it's on then you can start troubleshooting that circuit.
Post again.
Willcox
Le Mans Master
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From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
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On the starter, there is a black wire with a large terminal, is that connected to a starter bolt or the battery positive terminal on the solenoid?
Thread Starter
Cruising
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From: sahuarita az
Thanks again to Brian, Pete and Willcox vette. I see I didn't tell you I had done the multi meter/fuse tests and came up a bust. Did just put the meter between the ground post and ground cable on vlts DC though, will now try the amp setting. I'll retrace my steps and try pulling and isolating all circuits. The black, large terminaled wire is grounded on a started mount bolt, but as starter isn't even in the car and drain is . . . ?
Le Mans Master
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From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
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http://www.nrjvette.com/johdotukset/...tte%201980.pdf
Team Owner
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From: Springfield MO
St. Jude Donor '07
If I had disconnected all terminals at the alternator and drain still persisted would that eliminate the alternator as a cause? Also found that ignition switch would rotate past the locking postion (towards driver) and the drain disappeared. Where is that courtesy light modual?
Are you using the key release? If you're just stopping at the first detent and yanking the key out, then it might be sitting in the "ACC" position.
Le Mans Master
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From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
OK Batman, if it is a bad ignition switch, how do you test for that?
Would disconnecting the harmonica switch prove the problem is in the column?
Would disconnecting the harmonica switch prove the problem is in the column?
Team Owner
Joined: Oct 2004
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From: Springfield MO
St. Jude Donor '07
I think that would do it, but you'd have to make sure there aren't any other connectors between the column and the main wiring harness.
Le Mans Master
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From: New Hill NC
The switch controls a lot of things in the car. Just because you unplug it and the draw goes away don't mean much, other than the draw is somewhere in one of those circuits.
There are things that are powered all of the time. There are things that are powered only when you turn the switch to on or acc. You need to methodically check each circuit until you find the culprit. The fact that you had the meter on Volts instead of Amps when you checked makes me think your previous results are suspect. The fact that you have the starter unhooked makes me wonder why anything works unless you have the hots hooked up down there. Thats where the power comes from. Go back and check the fused circuits. Go back and check the alternator.
There are things that are powered all of the time. There are things that are powered only when you turn the switch to on or acc. You need to methodically check each circuit until you find the culprit. The fact that you had the meter on Volts instead of Amps when you checked makes me think your previous results are suspect. The fact that you have the starter unhooked makes me wonder why anything works unless you have the hots hooked up down there. Thats where the power comes from. Go back and check the fused circuits. Go back and check the alternator.
Team Owner
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From: Springfield MO
St. Jude Donor '07
The only reason that the ignition switch seems suspect is that a lot of them have been abused over the years (people who yanked out the key without knowing how to use the key release, for instance), it's a high-wear part, and it seems to be showing some flaky behavior already.
Le Mans Master
Joined: Jan 2000
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From: New Hill NC
The only reason that the ignition switch seems suspect is that a lot of them have been abused over the years (people who yanked out the key without knowing how to use the key release, for instance), it's a high-wear part, and it seems to be showing some flaky behavior already.
Last edited by wombvette; Apr 26, 2012 at 09:12 AM.