Yesterday and today I worked on wiring the mirrors. After prepping/modifying factory wiring, I started working with the wiring supplied by Boost. I didn’t like the running light harnesses they supplied because the fuse holders would have ended up in the door or in the door jamb, so I extended them 14” so the fuses would be easily accessible under the dash. Here’s where the fuse holder sits on the passenger side.
Tapping into the turn signals wasn’t as bad as I expected. It was easy to tap into the wires at the turn signal switch connector (the light blue and dark blue wires). I tapped into the dash harness side even though it would have been easier to do the switch side, but if I ever have to replace the switch, I didn’t want to have to also re-do the mirror wiring at the same time.
I tapped the spotlights into the cargo lamp switch. No pic, but I just cut the existing terminal off and crimped a new one with the existing wire plus the 2 mirror wires.
Fishing the harnesses was a lot of fun, but a necessary step of course. The last hurdle was repinning the mirror plugs. When I first tried them out, the Left and Right functions were reversed. I had read of this before, so it wasn’t a total shock to me. I think it’s just an issue with the 91-94 trucks, but can’t recall for sure. I had to flip-flop the red and green wires. This is how that looked after moving them.
Success. Everything works as it should.
And here’s the factory schematic for the mirrors, just for funsies.
