I dunno Dan. When I got the drivetrain out of the donor, the former owner was parting the car out. I got the dash harness as an afterthought. Some time later, I decided to swap to a Regal dash, but it had no harness. So I put the two together. That pink wire was cut prior to me getting the harness. I was just puzzled having never seen a wire out the front of the fuseblock and was pondering removing it. No matter, the dash is in now so I'll just coil it up and tuck it away since I have no rear defrost. Might be handy one day.