I have been experiencing a problem with my 03 G35 Sedan for several months now. When the car sits for several days the battery is drained and the car won't start. My first move was to replace the battery which didn't fix it.

I tested the alternator and it appears to be working fine.

I read that some 03 Bose Amplifiers go bad and cause this battery drain problem. So I disconnected mine, but the problem still occurs.

Does anybody have any suggestions on where I go from here? The car is no longer under warranty and I enjoy the challenge of trying to figure these problems out on my own, so shoot me any ideas you have.

your stock battery may be in need of replacement.

My '05 had the same issue, and I put a new battery in and I don't have nay issues. I couldn't find anything that was draining the battery....I think the stocker just sucked and wouldn't hold its charge for very long anymore.

^^ I think he said he already replaced it

I got the same problem after 3 days of not starting the car.

Optima Red Top FTMFL

with all my electronics it gets drained very quickly.

go for the optima deep cycle Yellow Top. that thing can run all day

hey man, I dunno if you have daytime running lights, but in Canada we do, and my DRL module was malfunctioning, leaving my lights on all day while parked. It drained 2 batteries before the stealer finally found out the problem. I have an 03 as well. You might want to look into that

Are you talking about with the car off? If so you are correct, the Red top is not made for deep cycle use like the yellow.
I have a red top on my G with extra lighting, JL 1000/1 & 450/4, etc, etc and have not had any problems with it.

Just for clarification on my original post. This problem occurs with the car off. There are no day time running lights on my car. There is something drawing significant current even with the key off. Nothing has been modified in the car, it has the factory Bose stereo.

I appreciate any ideas you can provide...

stock alarm ?

if possible put a multimeter inbetween the power line and see how much of a draw we're talking about.

ppp

If you have a DVOM then you can test the electrical draw on the car...If you don't then you can go to Autozone and those guys there should have one and they can test it for you...Also, I think it should be .002 amp for a normal parasitic draw...Anything more then that will cause the battery to go dead...If you don't start the car for more then a month then unplug the battery and put it on a trickle battery charger to maintain the battery for long term storage...

Here's how you test it...

http://www.acuraworld.com/tsb/1992/B92-003.pdf

I used to work for Acura...but this applies to more cars...Simple electrical diagnostics...Remember its in Milliamps...Make sure that the DVOM's internal fuse is not blown. Common mistake when people try to do an electrical draw tests...

yea-thats true.

however i was expecting some improved performance over the oem battery...it has amazing starting power but nothing else that is truely significant