Battery Drain

duscarter · December 19, 2008

My 1994 Chevy Siverado has a slow parasidic drain. If I leave the battery connected it will drain in 3 to 4 days.

The multifuntion switch is giving me problems too. The lights and windshield wipers work when they want to. I hope that is an unrelated problem that I can fix later on.

I did the test light on the negative battery post while unplugging fuses test with no results. Is there anything else I can do to track down the drain?

Edit: The alternator and battery both tested good at Autozone.

Draenor · December 19, 2008

These are the worse things to diagnose. The only way I have found to start me on the right track, is to pull fuses till it stops. Then I work my way on what was disconnected.

duscarter · December 19, 2008

Man you are everywhere! I was just piddling on this until my new harness comes in on the SUV.

I unplugged the neagative post and clipped my test light to the cable. Then put the pick into the negative post. It stayed lit while I pulled every fuse.

I might take it to another shop to load test the alternator.

duscarter · December 20, 2008

I think I am going to throw the test light in the trash. Found this test on Youtube:

The guy has a pretty good diagnostic flow chart on his website. The cigarette lighter is the likely culprit. I will know for sure after leaving the battery connected.

Got to do a brake job on it, then decide if I want to try and tackle that multifunction switch. There are some good instructions for a newer truck on the forum. It should be easier on a 1994.

duscarter · December 22, 2008

The battery drain is fixed!!!! One project done.

jimlem · December 22, 2008

The battery drain is fixed!!!! One project done.

What exactly was it and how did you fix it? You don't mean it was just something you left plugged in to the cig. lighter do you? I"m sure that would have been your 1st item tested. Let us know what you found out. My stupid battery dies if I am doing a day-long project where the dome and courtesy lights are on/off but mostly on from opening and closing a door and re-setting the off timer. Or, 4 hours on a front end alignment rack where they had the brake pedal clamped down and that killed it really dead. So, like you I must figure I have something else going on too. Battery is only a year old. Alt. and batt. test good. You know, the usual mystery stuff. Any info appreciated when you have time. Merry Christmas.

Jim

Draenor · December 22, 2008

I think I am going to throw the test light in the trash. Found this test on Youtube:

Thats kind of what I do. Put my meter on and start pulling fuses.

The battery drain is fixed!!!! One project done.

So was it the cig. lighter?

pennzoil29 · December 22, 2008

I think I am going to throw the test light in the trash. Found this test on Youtube:

Thats kind of what I do. Put my meter on and start pulling fuses.

The battery drain is fixed!!!! One project done.

So was it the cig. lighter?

We may never know.

duscarter · December 22, 2008

I did the youtube test and narrowed it down to the ctsy fuse. The cigarette lighter is on that fuse, so it was the first thing I looked at. It was easy because you could pull the ashtray out to get to the wires.

Someone had replaced it before, because the wires were spliced and taped. I cleaned it up and crimped the wires. My voltmeter told me everything was ok. It has been a couple of days and the battery is staying charged.

I know nothing about automotive electronics. I don't know why the loose wires would cause a drain. It looked like a hack job to my untrained eye, so I fixed it. The $20 DVM from Autozone was a good investment.

jimlem · December 23, 2008

I did the youtube test and narrowed it down to the ctsy fuse. The cigarette lighter is on that fuse, so it was the first thing I looked at. It was easy because you could pull the ashtray out to get to the wires.

Someone had replaced it before, because the wires were spliced and taped. I cleaned it up and crimped the wires. My voltmeter told me everything was ok. It has been a couple of days and the battery is staying charged.

I know nothing about automotive electronics. I don't know why the loose wires would cause a drain. It looked like a hack job to my untrained eye, so I fixed it. The $20 DVM from Autozone was a good investment.

It's too bad you got stuck with a hack job but also very, very lucky in a way. There have been threads on here where highly knowledgeable auto electronic guys have chased their tails for a long time and still were not sure if they'd actually located the source of the problem. That's why I or someone, always wants to know what or how you did it when you report that you fixed it. You are right about the DVM being a good tool to own (you WILL likely use it again) and now you are no longer quite the newbie on auto electronics. The next will one will be a bit easier and so on. I am glad you found and fixed it and the battery is holding its own again.

I too, do not qualify as an expert but a couple of things may have been going on under that tape. All it takes is two wires touching that are not supposed to. Also a tiny gap between wires (wires not solidly crimped together) sometimes is not enough to break the circuit like a switch but can cause the voltage to build up to overcome the resistance of the gap and creating even more current flow. Kind of like voltage building to jump the gap on a spark plug, but on a much tinier scale. What ever the case, congrats and thanks for taking the time to let us know. It's a nice early Xmas gift. Happy holidays.

Jim

duscarter · December 23, 2008

Thanks Jim! Good luck with yours.

I've got work to do on my daily driver before I do anything else to this one.

Mike G · December 30, 2008

I too experienced this draining issue once, found out the under-hood light was not shutting off. I was in the dark, then I figured this one out (-ouch).

--Mike