Power stays on

[jyoo]

Hey guys. I have a 1987 635csi and I have a problem I can't figure out. The power stays on the car even with the key out of the igniton. I've just been taking out my face plate for my aftermarket headunit every time I shut the car off so my battery doesn't completly drain. I've figured it was a faulty igniton switch and got it replaced. Now here's where I am stuck. The igniton switch was not the problem and the power is still on. What other possible problems could be causing this? Please help!

[alpinacsi]

When you say the power stays on: what power? Did this just start on its own or after something was done? Has it done it since you got the car? is it stereo related?

To help with any issue: you need to give as much as you can to help us sort it out. Who replaced the ignition switch and did they check anything out?

Welcome to the group.

[OBwan]

If its the stereo that's always on then the aftermarket stereo was wired to a constantly hot wire.

[carnut1947]

Need to clarify symptom! what stays on? Dash warning lights, stereo? Engine?

[Trevor M]

Find the wiring diagram for your car here. It will be a valuable tool to help you diagnose this problem.

http://wedophones.com/BMWManualsLead.htm

Could be a bad ignition switch or a stuck on relay but I would most suspect the aftermarket stereo.
If you go through the fuse box and pull one fuse at a time until the drain goes away will point you towards which branch of the electrical system to focus your efforts.

[DesktopDave]

If you pull the faceplate off the head unit, the power drain stops? Bad head unit? There aren't a lot of things powered up with the key out, but the stereo memory could be bad. I'd put an ammeter on the stereo fuse terminals and see how much current it's pulling with the key off. Should be very low, I'd figure less than 100mA.

[carnut1947]

Let's wait till he answers please.

[Sansouci]

Could it be a short in the harness or the fuse panel?