Battery Keeps Dying

[robman78]

I have A 94 BMW 325I convertible. For the past week I keep having to jump start the car to get it going in the morining and sometimes in the afternoon. I tried changing the battery with another one from a rebuilt battery shop to see if that helped. It didn't I asked around and several people say that it seems to be a common problem with some BMW's that there is a short under the dash. Is this true. Is this something that can cause my battery to discharge?

[OwnedbyDuncan]

Rebuilt battery??? Have you had the charging system checked? Could be a bad alternator. Bosch alternators last about 130k miles and Valeo may last to 100k or so.

Interstate batteries last I had one for approx 7 years before I replaced it with another. Usually I replace batteries somehwere between 36 to40mos just to be save. I forgot and it dies on me after 7 years.

You need to have the car checked out by a competent mechanic not Sears or any place else selling batteries.

BTW have you checked the to make sure the battery has water and the both the postive and neagtive wires are tight?

My guess is your alternator is dieing.

Dave Apker
Why doesnt Vegas offer comps for shopping?

[robman78]

What do yu think about a short in the system that causes the battery to drain. I've heard that there is a common issue in the dashboard that causes a short. Is this true?

[OwnedbyDuncan]

I have never heard of it. To the simple stuff first like having the charging system checked and then move to weird stuff. Unless the person who told you this a BMW tech I would take it with a grain of salt. Why did the short all of a sudden appear? Doesnt happen that way! How many miles are on your car? But first check your battery connections.

And use a decent battery you have no guarantee the one in your car now is any good. Or will hold a charge.

If your battery is more than 3 years old replace it. If that doesnt take care of the problem have the charging system checked.

If you have access to the right tools you can test the charging system yourself.

Isnt there a DIY this weekend or next?

Fred

[robman78]

Thanks, I bought a brand spankin new battery lets see how that does. If not guess i'll be busy this weekend.

[Scotty]

Just remember, a bad alternator can trash a new battery pretty fast. I fell for this trap last year - two batteries down the crapper before I realized the alt was the problem.

[chicane]

I have A 94 BMW 325I convertible. For the past week I keep having to jump start the car to get it going in the morining and sometimes in the afternoon. I tried changing the battery with another one from a rebuilt battery shop to see if that helped. It didn't I asked around and several people say that it seems to be a common problem with some BMW's that there is a short under the dash. Is this true. Is this something that can cause my battery to discharge?

Alternator. Remove it from the car, take it down to AutoZone or AdvanceAuto and have it tested.

[AlfaEric]

I have A 94 BMW 325I convertible. For the past week I keep having to jump start the car to get it going in the morining and sometimes in the afternoon. I tried changing the battery with another one from a rebuilt battery shop to see if that helped. It didn't I asked around and several people say that it seems to be a common problem with some BMW's that there is a short under the dash. Is this true. Is this something that can cause my battery to discharge?

My battery kept getting drained. I discovered it was the interior lights (the ones that go on when you open the door). Even though the door was closed, they were draining the battery. An electrical drain can be a pain to diagnose. There are plenty of DIYs posted on the net on how to do it. It's usually something like... find what the drain should be normally (when off - there will still be some drain for memory items like your radio), pull a fuse and re-check. Keep pulling fuses until the drain goes to an acceptable rate. Once you find the fuse, lookup what that fuse covers and start tracing from there.

Have you had any electrical work done in the past few months (new radio perhaps)?

---Eric

[magnetic1]

Check the trunk light... that sucker was draining my battery for the longest time!

[///MARINE]

Robman78,

I had/have this problem on my 1992 325i sedan as well as my 1995 325i convertible. I found that the previous owner of the '92 had apparently "hot wired" the windows switches directly to the battery. Heaven knows why. Undoing the rigged wiring fixed that. As for the convertible, the trunk lighting was the culprit as previously stated by a fellow member. Do some "C.S.I." work and you will soon find the problem. Good luck!