2001 325i - Battery used if radio is left on after car turned off

Someone has changed things so it runs off battery supply.

Do you mean the radio/CD continues to work with the ignition key removed?

Is it the standard radio? If so it should switch off with the key. Or does on mine.

But I have an aftermarket unit in another car which although switching off with the key does allow use without it if you then switch it on again - like say when leaving passengers in the car. However it 'times out' in these circumstances.

Thanks for that input! Can you think of a reason someone might want/have to do that?

Yes and no - power seems to be cut from the radio (so it won't work and no lights are lit), but if left on before the car is shut down, the battery gets drained. Strange, I know.

Yep, its the "BMW Business CD" standard and seems to do the same thing yours does - switches off when the key is turned to the off position and pulled out. But then the battery drains. If the radio is turned off before the key is switched off, the battery is fine. It's happened a few times - but enough to allow for the isolation of the Radio as the culprit. So maybe there's a short somewhere?

They have a power amp in the boot. I dunno how it's actually switched, but it won't get its actual power from the radio switched circuit so could conceivably be staying on.

Thanks Dave! I'll check that out.

Meanwhile, I had to make a 45 minute drive to jump the car at my wife's office last night . She swears she turned the radio off, made sure the trunk lid was closed (this was another thing the dealership told us to do to make sure the battery wouldn't drain). I might end up having to take it to a mechanic so it can drive him/her crazy for a while.

I think I mentioned it on another thread but on mine it was actually one of the door locks not going all the way down. Ah, German engineering ;-)

Sure the owner waits for someone at a train station / airport / school gates or leaves kids in the car while they shop and wants the radio to work without leaving the ignition on / key in the car.

Could just be a replacement unit and wired up wrong.

Are you sure it's being turned off. some folk just turn the volume down. However this shouldn't drain the battery as the ign will turn off the radio and other systems.

I would run a test on the current drain with ign on & off and radio on & off.

Failing that get to an auto electrical guy that really knows BMW.

Weird.

Hugh

Ashtray lighter in our 2001 325ci is powered all the time. Radio could have been reconnected to that feed.

I put a GPS in and plugged in there and noticed the GPS never went off unless I turned off the switch on the GPS.

Vito