E38 7 Series gremlins

[Jammez]

Hi Folks

I recently acquired a 730i which I was going to be taking the engine from to use in another project (a TR7). As it turns out the engine isn't going to fit without a fair amount of hassle & if I'm being honest it would be a real shame to break the BM as it's in very good condition.

I'm now getting the car back on the road with a view to selling it, it's been sitting for a few year but it sailed through it's MOT with no probs. All the major stuff is fine, it runs like a dream and cosmetically it's cleaned up really nicely but there's a few electrical things that are playing up.

One door refuses to lock no matter what I do, I'm assuming it's the lock motor gone, any pointers before I start stripping down the door?

The second thing is the whole audio/ heating unit. Stereo works fine when you first get in but after about 10 mins it refuses to change channel, turn off or anything (was stuck listening to radio Scotland all the way to work this morning!). Once you turn off the ignition it's fine again for another 10 mins then the same happens.

Heating controls work but the 3 buttons to switch on the heated screen, air con & recirculation all seem to have a mind of their own! Press the buttons & the indicator light comes on for a second, then turns off. If I hold the screen & recirculation buttons on for a few seconds they seem to then stay on ok, but this doesn't work with the air con.

I know the electrics in these older BMW's can be fun and games but I'd like to be able to sell it with all the stuff working so any help on these would be really appreciated.

Cheers

James

[ODJ]

Try replacing the ignition switch they are plug and play and available for a few £ on eBay. Cured a host of problems on my e39

[fluffnik]

ODJ said:

Try replacing the ignition switch they are plug and play and available for a few £ on eBay. Cured a host of problems on my e39

Strange but true - this might well fix all the problems.

[williamp]

I agree. Try this also: start the car, pull down the sun visor and open the mirror, so the light should come on. Anything else odd happen??

See here:

http://www.bimmerboard.com/forums/posts/244045

[Jammez]

Got the part ordered & I'll let you know if it works! For £15 it's worth a punt!

[gf15]

The sat nav/ radio on my E38 740 used to freeze like yours about once every three months.
Take the sat nav & radio fuses out (they were in the boot on the drivers side) and leave them out for 12 hours and the issue was cured for another 3 - 6 months.

[Jammez]

OK folks managed to get the door lock working, just stripped the mechanism & motor down, cleaned it and put it back together & it's working fine. I've replaced the ignition switch and the car now wont start, all the lights come on but not turning over. Do I have to reset anything after having the battery disconnected?

[Jammez]

Car working again, but the ignition switch change hasn't cured the electrical problems it's just changed them!

The air con & demister now come on and stay on sometimes! Other times they go off after a couple of seconds & I now have the ABS light coming on!

Gotta love electrics in big german barges, still at least the doors looking now!

Edited by Jammez on Saturday 15th October 17:19

[MarkwG]

Could be a dieing battery - e39s are quite sensitive to battery condition; if you disconnect it & fully charge it, (if it acts like an e39, which I think it's closely related to) it'll reset itself & that may cure the electrical glitches.