Hey y'all! I'm new here. Here's the lowdown:
I have a non-turbo 1988 740. It's a piece of crap, mostly because I'm having brake and wiring issues. I'm a dummy and I got highway robbed when I bought it, but I was desperate...
Anyway, the kid that sold it to me busted out the original stereo and put a CD player in, and I think he screwed some things up whilst doing so. The left turn signal used to shut the engine off, but I got that fixed. Other odd wiring defects: the right headlights won't turn on, but they will if the high beams are on. The windows won't go up or down if the engine is on, but they will if the key is in battery mode. I just had to pay a mechanic 700$ because the car randomly wouldn't start one day, turns out the fuel injectors all of the sudden stopped making a full circuit, but were putting out adequate volts.
And now for the new problem: I was coming home today and suddenly ALL of my dash warning lights came on and wouldn't go away, even after shutting off and starting the engine again. Engine is working just fine.
I'm taking it back to the mechanic in a couple days, and I want to throw some ideas at him, any suggestions?

 

If I were to guess--and this is just that--I'd say when the guy was messing with the radio, he really screwed up your wiring harness. The main fuesbox in that car is right under the radio, so if he cut the wrong wires, and put things back together... well, just about every important wire in the car meets under there. Doesn't sound like fun to me.