bmk04tsx

I have posted in other threads and asked the question in various forms with no responses yet. This is partially because I am still investigating and narrowing down possibilities so bear with me.

For about the last month or so i have been noticing that my battery has been drained after sitting for 1 or 2 days. It has always started but has been slow to crank. I would turn off all accessories (heater and radio), wait a minute and try again and it would fire up, still slow cranking but enough to start. The old battery was about 3 years old (autozone, duralast gold) so i bought a new one. I noticed that the acid was low after i removed it, but decided to replace it anyways, so much for "maintenance free".

I started noticing this after having issues with the factory alarm. During a rainy day, the alarm would go off at random. On other occasions, the horn would not beep when i locked the car. I have since determined that my hood latch sensor is dead. I removed the latch, cleaned it up and reinstalled it but the sensor was still crap. I disconnected the harness for now to keep the neighbors happy.

The only aftermarket item on my car is an "XM Commander" which is wired in through the fuse box with jumper wires to power and accessory, no problems with this device indicating a short or fault.

Since replacing my battery and disconnecting the hood latch sensor, i have not had any alarm issues. I have noticed that it is still slow cranking (just not as bad as before) after sitting for 1 or 2 days.

Should i use a jumper wire at the hood latch? This should not matter, but maybe it does. When i checked the trunk sensor, the circuit is closed when the trunk is closed, allowing 12v to flow through it. When you disconnect the hood sensor, it does not affect the alarm system, but also doesn't allow the 12v signal through.

Does anyone have any other suggestions for testing or diagnosing this issue. I'm sure the new battery will help cold starts but i have to wonder for how long. Thanks for reading, any input would be helpful.

Simba91102

I wonder if you haven't got any responses because no one here can diagnose your problem sight unseen. Even then, the electrics whizes (of which I'm not one) may beg off. It sounds like you already know (or should) that it's not the battery. And replacing parts until you trip over the right one can be expensive and time consuming. I'd say your OE alarm problems are your best clue, but if it were me, I'd just take it to a dealer, tell them what you've related here, and let them fix it.

bmk04tsx

Well i'm not taking it to the dealer quite yet. I know how to work on cars and can pretty much fix anything, after the proper diagnosis of course. The purpose of this post was to see if anyone else has or had the same problem. I'm just looking for suggestions. The standard response of "take it to the dealer" is not helpful for someone who enjoys working on their own car and cannot afford a dealer visit every time something goes wrong. My problem might have been solved by replacing the battery and disconnecting the hood latch... i admit i might be a little paranoid. If someone has experience with issues like this, chime in! If not, i'll figure it out eventually and let everyone know for the NEXT person who has similar problems.