Ok here goes, Iv been trying to nut our this issue all day with my new 92 940se wagon. I just rebuilt a motor which went into a cheap car that was overheated. the owner didn't look after it very well etc but the body is good. Now with the new motor in and running happily i looked at my dash and see, well not much at all in the form of temp guage not registering any temp. tach not working, also speedo seems to not be working either, also the horn and fuel guage! All the indicator lights in the bottom row that usually turn on just before you start don't light up before you start. Everything else works fine clock and lights wipers etc. I had one coil explode because i left the key on and it didn't like that very much, but have replaced it now else the car wouldn't run.
Funny thing when you hit the over-drive button temp guage goes up, not all the way just a little bit? also the indicator bulb on the dash lights up as well.
the dash is from my old car 92 940se and it all worked when i pulled it out!
I cleaned all the earth under the bottet and behind the drivers kickwall with a wire brush and added conductive past, anyway they all looked fine in the first place and it didn't change anything.
The only other thing i can think off is the main earth got a little pull when i was lifting the old motor out. forgot to detach it!
That's all i can think of at the moment. any help or ideas would be greatly appreciated. i spend hour on here trying to find something, but havn't come across a solution yet.