Battery problems

[calex]

Hi im now on my third battery in my 325, if i start it every day its ok, if i leave it 2 days the battery is to flat to start, i just dont know why they go flat. Nothings left on, its not the stereo its not the clock or boot light, im stumped anyone have any suggestions that would be great. it was converted from 1.6 to 2.5 years ago but dont think that would have anything to do with it. thanks

[milescook]

Have an alarm fitted? Mine killed the battery in 3 or 4 days.plebt of posts here about usual suspects.if you have a millimeter that can help diagnose by plugging fuses and checking readings.do some searches here tons of advice

Millimeter even

[mark_i]

worth checking the alternator.
with the ignition off, they can drain a battery when the diode pack is defective.

[Billwill]

If you cannot find a Millimeter get hold of a Multimeter....put it on DC Amps and put it in series with the battery...do not start the car.

With everything turned OFF you should get a reading not more than about 30 mA.

Pull the fuses out one at a time to see which fuse makes the biggest drop in current when pulled out...that will tell you which circuit is at fault.

As stated...usual suspects are alarm/immobilisor, boot light and bad alternator but you could easily have ashort or partial short somewhere.

[Brianmoooore]

Make sure you have the keys with you and/or a window open before you disconnect and reconnect the battery. Some alarm/immobilisers lock the car when the battery is connected, and you wouldn't be the first to find out this the hard way.

[calex]

Thanks for the help, doesn't have alarm or immobiliser so that rules that out.

[Brianmoooore]

Thanks for the help, doesn't have alarm or immobiliser so that rules that out.

Unless you're 100% familiar with the wiring of your car, I wouldn't be too sure of that! Very, very few E30s haven't had an alarm/immobiliser at some point in their life, and there are plenty of them out there that their owners aren't aware of.

[TPS]

I had an auto electrican come to me, I had a similar problem, turned out they were 2 old Immobiliser circuit/wiring still buried in the loom, it had been butchered by amateurs.

[calex]

I finally found the problem, it was fuse number 28 draining the battery so it got taken out, no idea wot it was for but everything that i need to work works so its all good. cheers for the help and the info.

[kam-325i]

fuse 28 is for Cig Lighter, Elec Aeriel, Door open window lifts.

[Brianmoooore]

fuse 28 is for Cig Lighter, Elec Aeriel, Door open window lifts.

Plus factory fitted alarm/immobiliser.