Just bought an 89 Sedan Deville, but it didn't come with the rear defroster (honestly didn't know you could get a Cadillac without that feature). My question is this, does anyone know if these cars are prewired for this option? I have 2 donor cars that both had it, and I'd like to just have a glass shop swap the rear windows, and then all I would have to do is connect it and swap the climate control units. Appreciate any info you can offer.

 

most cars had the same harness. too expensive to make different harnesses.

look in your trunk for a harness and a unused connector.
also, does the car have a dashboard SWITCH to active it?






.

 

The button for it is missing from the climate control unit (that's how I discovered the car didn't have it). At the very least, I assume I would have to swap in a climate control unit that does have the button for rear defroster. I won't know if the harness to the unit is wired for it until I pull the units from both cars and compare the connectors. In the trunk, I assume you mean somewhere between the rear seats and the carpet in the trunk.

 

one use to be able to have a rear defog installed. some local audio shops in your area. they will be able to adapte a switch for you also....
rickyd

 

I want to be able to use the factory switch if I can, and I guess I'm assuming it'd be cheaper to put a window in that already has the defroster lines on it, but I don't know about that.

 

the installer will be able to use the factory switch if you want.