I have a 1987 760 turbo. In cold weather none of the dash indicators (except for seatbelt lamp) will come on when I first turn the key and the car won't start. After a few rotations of the engine, I hear a relay click then the engine fires and runs just fine.

Today I looked down while driving to notice that most of the idiot lights were on and the charging guage is bottomed out on the low end. I am assuming bad ground or bad alternator or voltage regulator, although I replaced the regulator a couple of years ago.

Question is, which ground wire is most suspect if the regulator doesn't turn out to be the problem?

Oh, and is it safe to park with the key off, or should I disconnect the battery until I figure this out?

Don't want to burn down the car.