Battery drain Pontiac Bonneville

wilson ind · Oct 18, 2020

Have constant battery drain on car. Sometime ago there was a post that problem was ignition switch. How can I remove the ignition cylinder with the key? Any other thoughts? Already removed fuses and unhooked alternator. Marks a good old car useless!!! Thanks to all.

wore out · Oct 18, 2020

It might be helpful if you would have posted the "year" of the car.

Try going to You-tube armed with that info, I'll bet you can find a whole slew of videos on the subject.

David G · Oct 18, 2020

How long does it take?

old · Oct 18, 2020

Wife's Chevy van had that problem and I found it had a bad door switch so a couple light where staying on. I removed the bulbs and problem went away

ss55 · Oct 18, 2020

Depending on the vintage, early 1990's computers and radio would drain a battery in a couple months. A failing radio or poor battery can shorten drain times a lot.

Steve@Advance · Oct 18, 2020

How are you checking for drain?

If it's new enough to have electronics, timers, control modules, then it has to be checked with an amp meter.

All the electronics have the potential to have "time out" features, which need to have battery voltage to them in order to complete the timing feature, then the drain drops to a milliamp level.

To protect the meter, start out with an amp setting high enough to handle the worst case of a heavy draw, say 10 amps.

Be sure the doors are closed, everything off, hood light disabled. Give the time out enough time to complete, 5 minutes or so. Have the meter in place between the battery and the load, remove the cable without breaking the connection, letting the amp meter carry the load. This is easier done away from the actual battery post.

If the meter can't read the load, start working down to a lower amp setting until you are in the lowest range or milliamp range.

The goal is around .05 amps, or 50 milliamps. It can be higher if it is a daily driver.

If there is an aftermarket alarm system or radio, that would be the first place to look.

RayP(MI) · Oct 18, 2020

I had a Ford Bronco II that about drove me crazy. Would only drain the battery when wife was at work. Turned out to be a defective regulator in the alternator. Only time it would trigger was when she parked the car and then opened passenger door to get her things out. That would trigger the dome light, which would energize field coil in the alternator. Of course, without engine running, would discharge battery during her shift. Took my rebuilder friend more than one new regulator to finally solve the problem. He returned several potential bad regulators to manufacturer and changed brands. Odd ball defect!

John Garner · Oct 18, 2020

Had that problem in a Mercury . . . turned out to be a shorted switch for the glove box light.

JDBRIDER · Oct 18, 2020

Had a 73 Pontiac. You didn't say what year yours is. I had a battery drain. I discovered the drawer type of glove box sometimes wasn't getting closed all the way which caused the light to stay on. It was closed enough that you couldn't see the light. I solved the problem by taking the light bulb out.

used red MN · Oct 19, 2020

Looks like he is talking about a 2001, per his post in the link...10th down.. I‘m not sure if those years still used the cam and rod down to the actual contact switch on top of the lower steering column. I know 99 still did. I think you are going after something that does not happen often, a rare issue that gentleman had with his vehicle in that post. How long have you had the vehicle? Does the horn work? If not have they been disconnected? GM had a problem on some vehicles where the horn pad in the steering wheel would short or make contact in extreme hot or cold. The horns would be disconnected but the relay would still be drawing and drain the battery. Of course the vehicle would be fine and run for months until the extreme condition was encountered and the relay would again flatten the battery. Also, in the other post you mentioned pulling the fuses one at a time to check for the battery draw. If by chance you have more then one circuit causing the problem that method won’t find this issue. You need to pull a circuit fuse and leave it out until you have them all out to determine where the problem or problems are.
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Battery drain Pontiac Bonneville

wilson ind

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wore out

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David G

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old

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ss55

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Steve@Advance

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RayP(MI)

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John Garner

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JDBRIDER

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used red MN

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