had a friend put in a heater core in my 91 Audi 200 turbo. and now my stereo is screwed up....how do get a code if needed///and how do I put it in?

 

It should be in your radio manual, if you don't have that anymore you have to take it to the dealer and have them pull the radio and get the code from Germany.

 

I am more importantly concerned with the fact that my blinkers and windshield wipers are not working now. Does this mean they have to take the dash back out??

 

Probably not, you probably have a blown fuse or something. Someone might have accidentally ripped a wire out of a connector too, but i doubt it.

 

The code should be in one of the manuals. The directions are also in there. If you do not have the code, you will have to take it to the dealer and they will provide you with a new code. They charged me 100 bucks to get the damn code from some damn database. I had the same problem and the "SAFE" mode initiated when I detached the battery. As to the blinkers and wipers, my best bet is to chech the fusus.