It's an 89' Firebrd that did not come with rear defrost. It's got a harness on the back side of the instrument trim panel that goes to the rear hatch release switch. This same harness has another plug that is not used. The plug is screwed into the trim panel and has one of the cover pieces where a switch would be. I need to know if this plug is meant for the rear defrost or for the switch that was part of the Bose system.
If it's for rear defrost will the harness that runs between the dash and the rear hatch also be there? Thanks to whoever has this knowledge.

 

What color are the wires going to the plug in question?

Tim