Battery Drain

[Roger Frazee]

Please pardon all of my newbie questions. I'm still getting to know my TC. My problem jour is a dead battery. There is a constant 7 milliamp load on the battery that causes it to go dead in 2-3 days. The previous owner removed the bulbs from the trunk lid and the hood, so he must have been trying to find the problem too. I disconnected the pull-down motor, but the load still remains on the battery. Any suggestions on where to look next?

[Digger914]

Please pardon all of my newbie questions. I'm still getting to know my TC. My problem jour is a dead battery. There is a constant 7 milliamp load on the battery that causes it to go dead in 2-3 days. The previous owner removed the bulbs from the trunk lid and the hood, so he must have been trying to find the problem too. I disconnected the pull-down motor, but the load still remains on the battery. Any suggestions on where to look next?

When the car is turned off there is always a draw on the battery for radio and computer memory. Hidden lights like glove box, trunk, hood can run you dead overnight, the smaller relay coils will take a couple days.

Electricity is invisible, lots of places to look for something like this, what have you got for tools?

Do you have the wiring diagrams?

How did you determine the 7 mill draw?

Experience chasing electrical problems or not, tools or not, experience with electrical or not, you can find this yourself but it might take several days to weeks depending on what you have to work with and how good you are with what you have. The shot gun method is to replace everything it could be, not always effective, even when it is, it isn't always cheaper than taking it into a shop. Best method for troubleshooting is the 50% method, divide the electrical system in half and keep doing that until you find your problem. Start by pulling your shutdown relay and see if you still have the problem.

[Roger Frazee]

When the car is turned off there is always a draw on the battery for radio and computer memory. Hidden lights like glove box, trunk, hood can run you dead overnight, the smaller relay coils will take a couple days.

Electricity is invisible, lots of places to look for something like this, what have you got for tools?

Do you have the wiring diagrams?

How did you determine the 7 mill draw?

Experience chasing electrical problems or not, tools or not, experience with electrical or not, you can find this yourself but it might take several days to weeks depending on what you have to work with and how good you are with what you have. The shot gun method is to replace everything it could be, not always effective, even when it is, it isn't always cheaper than taking it into a shop. Best method for troubleshooting is the 50% method, divide the electrical system in half and keep doing that until you find your problem. Start by pulling your shutdown relay and see if you still have the problem.

I don't have a wiring diagram yet. I purchased a shop manual on Ebay, but it has not arrived yet. The seven milliamp draw was measured by placing a multimeter between the negative battery terminal and the negative cable. Seven milliamps seems like a very small draw, and may be normal, for all I know. Can you tell me the location of the shutdown relay? I'll start there. If that doesn't help, I'll start pulling fuses. Thanks for your help.

[Digger914]

You took your measurement for full current draw and 7 mill isn't enough to take down a good battery in 3 days. Do you have a good battery?

A sticking relay will and sticking relays don't always stick. The auto shutdown relay is under the hood top side of left fender right next to the diagnostic connector. If this thing sticks it continues to feed the engine / ignition module and you don't see or hear anything. Swap that relay with the one next to it and see if your symptoms change.

Have you ever noticed that your ABS is instantly ready after a full day of sitting? It's natural for it to loose pressure when the car hasn't been run for awhile and it should take a few, even 30 seconds or so to recover pressure, this would be a noticeable so keep it in mind. The ignition switch is at the base of the steering column; getting at it means pulling the covers, the actuator rod runs to the key-lock; there is a little play in the linkage; you don't always turn the key the same way every time you turn it off; they are position adjustable and if it's a little bit off it can leave things on; they also go bad; usually it's the adjustment. Pain and a half to get at so if you haven't done this yet; pay close attention to what happens when you turn the key to on after it's sat for a day, you should hear the fuel pump and the brake pump. If the shutdown relay isn't the offending item this is next and if it was easy to do I'd tell you look here first.

Edited September 17, 2013 by Digger914
grammer (see edit history)

[Nile]

You took your measurement for full current draw and 7 mill isn't enough to take down a good battery in 3 days. Do you have a good battery?

A sticking relay will and sticking relays don't always stick. The auto shutdown relay is under the hood top side of left fender right next to the diagnostic connector. If this thing sticks it continues to feed the engine / ignition module and you don't see or hear anything. Swap that relay with the one next to it and see if your symptoms change.

Have you ever noticed that your ABS is instantly ready after a full day of sitting? It's natural for it to loose pressure when the car hasn't been run for awhile and it should take a few, even 30 seconds or so to recover pressure, this would be a noticeable so keep it in mind. The ignition switch is at the base of the steering column; getting at it means pulling the covers, the actuator rod runs to the key-lock; there is a little play in the linkage; you don't always turn the key the same way every time you turn it off; they are position adjustable and if it's a little bit off it can leave things on; they also go bad; usually it's the adjustment. Pain and a half to get at so if you haven't done this yet; pay close attention to what happens when you turn the key to on after it's sat for a day, you should hear the fuel pump and the brake pump. If the shutdown relay isn't the offending item this is next and if it was easy to do I'd tell you look here first.

I had a similar issue - turned out to be the bulb in the spare tire compartment as the lid didn't always close completely.

I realize this doesn't solve the actual problem, but if you aren't going to use the car for a couple of days, just disconnect the torpedo shaped connector by the battery, then reconnect before use.