[lemans'n'gal]

i have a 03 monte ss as my daily driver. i have been having problems with the battery dying on me if i let it sit for a day or 2 untouched. i do not have hooked up that would drain the battery. i put in a new battery but that doesnt seem to help. hoping i could find the answer to what the problem could be....

[cobalt327]

Disclaimer- I am not in any way, shape or form, an electrician. Automotive or otherwise. So with that said, the following has helped me in the past:

One way to isolate where the current draw is coming from is to connect a VOM between the battery ground post and the chassis. Remove the battery ground terminal for now. Engine off, key off. Doors closed, hood light removed, if equipped. In other words, shut down the things that you can that use current.

See what the draw is.

Then by removing the fuses one by one, you will be able to determine what circuit is at fault. There are fuses both underhood and in the passenger compartment.

You can expect to see some draw from the circuits that supply the ECM, clocks, etc., but the guilty one should show up as a much larger draw.

Be sure you have a good, fully charged battery with good cables and the alternator is charging, to start with. If you're unsure about either, many part stores will check them both on the car for you- free.

Once you know what circuit it is, do the regular routine for finding a short. If you're unsure how to go about this, post back and I'm sure someone will lend a hand.

FWIW, in the past I've even seen a glove box light that wasn't turning off drain a battery, but this takes more time than what you're describing IF the battery is fully charged and is good. Same thing with an under hood or trunk light.

[kleen56]

It doesn't sound like there is a problem with the charging system but I would put a volt meter on the battery terminals anyways and see if the charging system is working properly. It should show at least 13.5 volts charging while the engine is running. If not, your charging system has a problem (alternator). If the chargine system checks OK, my guess is a short in the system, which is a real pain to find, especially with the wiring on a 2003 (there is alot of it). Not to discourage you, but if there is a short, I'd take it to a electronic diagnostic place where they can find the problem much easier than tracing wiring or replacing items. Just my 2 cents.