I have a 1999 Silverado and there is a connection up inside the overhead consule near the front windshield. Is this the connection I would need for the compass/thermometer rear view mirror option? Or is this for an optional " fuel milage computer" that mounts in the overhead (there is a blanked out area that looks like a computer could go there).

 

I believe the console in the '99 is also used in the Tahoes and Suburbans. If I remember correctly, the rear a/c controls go there.

 

I think you are right. Since I posted this question I have seen the same console with the rear A/c controls there. I wonder if the wires up there are then for the rear view compass mirror???

Thanks for your response.