My 93 SSEI is having overnight battery drain. I've tried everything, but cannot find out what would be causing this problem. The interior lights don't stay on, the stereo shuts down, everthing tuns off as it should once the door is opened. Does anyone else have this problem?

Help

Have you checked to see if your ELC is running too often?

I was thinking the same thing when I read the title. Some ppl'* ELCs run like crazy. Ask Will where the fuse is if you need it. (Sorry!!)

Could be the power door locks draining the battery. My 92 SSE would drain the battery after 3 or 4 days with it locked. With it un-locked (and in the garage)... no problems. Never did find out why it'* like this.

There is a way to check for parasitic drain. I believe you have to check for current flow across each of the fuses when the car is off to narrow it down to the parasite. There is a procedure in the service manual for this.

I had the EXCAT same problem... try to pull the relay for the power antenna... the long version is my 94 se got to t point if it sat for over 11 hours I could not start it... it finally went into the garage and the tech could not find a problem but on a whim he pulled the relay and the car has worked fine ever since... I just wished we had done that before it ruined a battery.

YES, I have seen this on a similar GM vehicle. If the antenna does not go down completely all the way to the stop, the relay in there will intermittantly try to lower the antenna. And it will do this forever. The one I worked on would try for about 15 seconds and then rest 15 seconds. It would draw 4 amps while trying. This will kill your battery in a day or two.

The way to diagnose these problems is to disconnect the battery and put a DC ammeter in line with the battery. With everything off, including all bulbs, you should have very little current, usually less than a tenth of an amp, depending on the car. If you see more than this, they you can try pulling fuses and such until it goes away. If you read as much as a couple of amps, then whatever is drawing power should be warm to the touch, because 2Amps x 12 volts = 24 watts. Just don't try to start the car with the ammeter in line, unless you want to see it go up in smoke.

Not sure if this applies to your situation, but your battery should have a minimum 770 cca. The senior tech at my local pontiac dealer confirmed this. When my wife took in my car a year ago to pep boys to have them install a battery, they only put in a 700cca. I just had it changed out for a 900cca.

For the parasitic drain test, the first 10 minutes after shutting the engine off will give you a faulty reading because the car lets you roll up and down your windows and other things that consume power. After 10 minutes, mine goes to 10 milliamps.

could be a short, might want to take your car to shop that does electrical