Battery Drainage Issues For 325i

[FeelGoodUnInc]

I'm posting this for a friend of mine who owns a 87' 325i.. car is in great shape and has less maintenance problems than my X5, but one major problem that's been hindering him is a battery drain problem.

Basically what he tells me is his car needs to be driven at least 15 miles a day otherwise his car will not start up (the battery dies). Now he's replaced the battery recently but to no avail and has replaced the alternator as well.

I just wanted to see if this has occurred to anyone else, hoping to maybe get some answers here before he has to take it down to a shop. Thanks in advance!

[clintonlover]

These vehicles kill batteries dead! In any case your friend should not have to drive his car every day to maintain a charged battery. Check for parasitic drain, I am sorting thru the same problem with my X right now, I used to leave for three or four weeks on end without even starting it, now it dies overnight!

[Bimmer Ese]

Does your friend have any aftermarket accessories, such as stereos and/or car amps? Maybe the car amp stays on after the car is turned off.

Never had any issues with my old E30. I'd check for obvious things, like the glove compartment light...maybe the switch is bad and the light stays on when the glovebox is shut or check to see if the fuel pump stays on after the car is turned off. Could be a faulty fuel pump relay. Does he have the correct battery installed?

Keep us posted.

Dan

[pete_c]

I've had a similiar issue with my E83. I've not had the issue with the E46. Did a detailed check on my E83 and never found any parasitic drain. I have a second replacement OEM battery sitting in the garage. It has 3k miles on it and its totally dead. I am attibuting my problem to a defective battery more than anything right now. I thought it might have been the BT module "sticking" but its not. The "test" has been leaving the vehicle parked without the trickle charger for periods between 1-4 weeks and being able to start vehicle with no issues or slow cranking. Another concern I found on the E83 was a stickly exhaust valve due to a hole in the vacumn hose. I've not read that this causes a parasitic drain though.

[MSUSaul]

There is a climate control auxillary sensor that causes the battery to drain. i replaced it and have had no problems. it is located near the glovebox on the passenger side. the part is about 60.00 dollars.

[pete_c]

Thanks MSUSaul. Is that on the 325i or X3 or both? I've taken out the glove box a "few" times in the X3 - easy to get to. (IE-In the E83 removed the glove box for the rear hatch switch and AUX audio installation)