[Fulltiming]

My coach has the newer digital gear indicator so things could be different but on mine, each gear display is activated by completing a separate ground at the transmission. My wiring harness has at least six ground wires, one for R, one for N, one for D, one for 3, one for 2 and one for 1. The wiring harness has a single power wire. To test mine, you apply 12 volt power to the hot wire at the transmission and then ground each of the other wires one at a time to see if the correct gear is illuminated on the dash display.

Again, my system could be completely different.