[amberdamber7]

Hello everyone! I have been reading these threads for a long time, but this is my first post. I am at wits end!

My 2001 Cavalier has been having a battery drain problem for almost 2 years now. The battery dies overnight, especially when the weather drops below 30F. It doesn't always do this, particularly in recent weeks, when it may die within 4 hours or be just fine after 36 (regardless of the weather). We have replaced the battery twice (once was a free switch via warranty), and taken it to the dealership for testing; they told us they "could not duplicate the problem, and that battery draw tests were within spec." Autozone has tested the battery and alternator, both of which were fine. Recently, I have tried cleaning the positive and negative terminals of the battery, and also replaced the blower motor resistor (based on some posts I read here). For 2 days, the car started perfectly, and I thought I had finally solved the problem! Then, for a week, it was dead every other day or randomly while it sat in the parking lot at work. It can sit for 14 hours and be just fine, then sit for 8 hours (after a 30 mile drive) and be dead.

We found, for a long time, that pulling the fuse for the instrument cluster while the vehicle sat actually prevented the problem. Now, however, that makes no difference (as if the problem has gotten worse?). I have an aftermarket stereo that uses the windshield wiper fuse as a switched 12v power source - this was installed for 2 years before the problems began, but doesn't seem related (I tried unplugging it completely for 2 weeks without effect). Otherwise, the car is stock.

If anyone has any ideas, I would greatly appreciate it! I have done everything I can think of, and nothing has worked yet.