Drained Battery

I am having trouble with my 2004 Impala. The battery will be doing fine for a few weeks or so and then suddenly, over night the battery will be dead. The only thing I added was the iSimple iPod interface, which does hook directly to the car's battery power. I'm concerned that this may be the problem.

After driving the car normally to and from work and some other locations over a few weeks, no problems. The battery seems perfectly full. It starts instantly and I have no electrical issues that I can see. I have not checked the voltage and the car does not have the dashboard meter for the battery.

Then, after driving on a Saturday morning to make a roundtrip of 15 minutes each way, on Tuesday morning, the battery is completely dead. I get no response for anything--no lights (at all).

Then, today after last driving yesterday -- about a 15 hour gap -- the battery was very low but not dead. The lights were very dim and the starter would not turn over--which may be the computer not allowing it to because the voltage was too low.

So I added my jumpstart battery pack to start my car and then drove off. Everything worked fine while driving so I'm thinking the alternator is okay. I drove for about 20 minutes so I'm hoping I can start it when I leave otherwise I'll use my starter pack.

Any suggestions on what to look for? I've let the car sit for much more than 15 hours before and it starts fine! The problem seems random.

The battery could be going bad. Have it tested. Check battery cables for loose or corroded.

The same symptons were occuring with my problem, My Body Control Module is shot, It draws power when it should be off. Does your clock loose tonnes of time overnight? If it does Your BCM could be going too i'd guess becuase I know of a few people who have had this problem. Otherwise, it could be an old battery. If your clock is loosing time, Test to see if its your BCM. In the Driver side Fuse panel, Find and pull out the BCM/Cluster Fuse and see if the battery's dead in the morning. Make sure to put the fuse back in before starting the car, it won't work without it.

Ignore the big arrow on the picture... The BCM/Cluster fuse is the red 10A fuse in the bottom left hand corner right beside the big grey Relay.

http://impalahq.naioa.com/HowTo/photos/Dash02.jpg

I have a 2000 Impala that gave me fits like this. It turned out to be the ignition switch. I could take the key out without having the switch in the off position. So oddly enough, the fuel pump stayed on, the radio stayed on and the battery would drain overnight. I never fixed the problem, just made sure the switch was actually in the "off" position. Good luck........