cyclopath, saw you posted in the mk3 issues thread.... and I remembered I needed to reply....
Well I determined that my reverse switch was malfunctioning.... Sometimes it would allow current through even when it was not in reverse. So I ordered a new one from fap99 and tested the switch. As I thought, when reverse is in gear the switch closes, and vice versa.
So I used the switched power coming from the 6 pin connector (the same on jumpered from the auto tranny harness) to power one side of the reverse switch. Then I hooked a wire to the other side of the switch and pulled it through the firewall down to the driver's side kick panel. Which is where you can find the two blue/black wires, one is in a smaller loom (going to rear of the car) and one is in the larger loom going to the TCM harness. I patched that wire (from the reverse switch) into the blue/black wire on the rear harness which goes to the reverse lights. The reverse lights are grounded at the light, so no issues there....
Things I realize: I didn't get to determine the exact source of the current for the 6 pin harness, so I'm not sure how much amperage the wiring is fused for.... For now I needed a quick fix, but I'm sure you can tap into one of the park or light sources in at the fuse panel or by the front lights harness. For as little as the lights are used, I'll take my chances.
From what I understand, the Relay that controls the reverse lights is tied into the TCM. One of the blue/black wires runs to the relay at the fuse panel, then the other goes to the TCM to activate or deactivate the relay as needed..... Cyclopath, I think thats what you were getting at.
You probably could just provide power to one of the old TCM wires at the tranny, and then just splice it over into the reverse lights.... Thus, elminating the need to pull a wire.
Modified by vwman099 at 10:43 PM 6-5-2006