Battery drain somewhere - is there a how to?

[Redsquall]

Hello guys
Is there a comprehensive to Tutorial on locating the cause of battery drain to eliminate it? My battery is just about completely dead. It probably took a few days to a few weeks to get to that point. I am not sure. I'm charging it back up now and will see how fast it drains. Thank you

[Horsebox]

You could charge it back up, unplug one of the battery terminals and put a DMM in series to measure the idle current draw. If you do this with the door open, make sure you push in the door switch so it thinks it's closed.

I think I got something like 13mA when I tested mine.

[Bitsyncmaster]

Pull your #12 fuse for the dome lights. That is the most likely cause for a battery drain that quickly. You can stick a current meter in that fuse socket to check all the lights go off or if pulling the fuse fixes the problem you know a light is not shutting off.

[SS Spoiler]

Or do an end run around the problem and put a battery cutoff
behind the passenger seat. Flip it on to go for a drive flip it off
when you get home.

[DMCMW Dave]

Short but more complex answer:

Put an inline ammeter in the battery line. Measure as described. Then start taking out all the fuses one at a time, and disconnect the lock module. When you disconnect something and the current goes away, you found the circuit with the problem. That's about all the detail that there is to it.

Most common problem is indeed the door switches, i.e. the door lights stay on all the time. Second most common is a failed lock module that either drains a slight current or actually engages the door lock solenoids until the battery is dead. Check the glovebox and trunk lights too, but pulling fuse #12 kills all the courtesy lighting so that's a good place to start.

A battery cutoff is a good idea as the normal drain of the car (clock, radio memory etc.) will typically kill the battery in a few weeks.

[Ozzie]

Short but more complex answer:

Put an inline ammeter in the battery line. Measure as described. Then start taking out all the fuses one at a time, and disconnect the lock module. When you disconnect something and the current goes away, you found the circuit with the problem. That's about all the detail that there is to it.
...

For OP: I show a picture in the first few paragraphs, and a general how to, here: LED Blog (http://delorean2109.blogspot.com/2011/07/going-100-leds-on-your-car-is-good-idea.html).
With that setup, just pull fuses out as Dave writes above, and you'll be able to narrow down (and quantify) the circuit of the the drain.

[Jonathan]

If you have your own single garage, or can use someone else's, you can put the car away like you normally would, close the garage door and turn the garage lights off and then look over the car while it sits in the dark. You'll notice pretty quickly if it is a dome light stuck on, and if you look for the door lights, you can sometimes see through a slight opening in the door seem between the door and the body as to whether there is any light coming from one of the receptacles. It's easy and simple, not very qualitative, but it is simple.

[David T]

If you have your own single garage, or can use someone else's, you can put the car away like you normally would, close the garage door and turn the garage lights off and then look over the car while it sits in the dark. You'll notice pretty quickly if it is a dome light stuck on, and if you look for the door lights, you can sometimes see through a slight opening in the door seem between the door and the body as to whether there is any light coming from one of the receptacles. It's easy and simple, not very qualitative, but it is simple.


A quick way is to put a bulb in line with the battery, ie, take off a battery terminal and make the power go through the bulb. it should light up. Keep disconnecting things until the bulb goes out. Don't forget to check the cigarette lighter, coins can get in there and short it out. Door switches are the first thing to check. I had one D and a door was filled with water shorting out the bulbs inside. What a mess.