[Oldtruckfanatic]

Its in the tail light harness On the automatic and column shift trucks. The four wires from the firewall running back that look like a trailer harness. On a trailer harness the 4th wire is white And Iits a ground. On our trucks its light green I believe. Brown= tail dark green= right turn/stop Yellow = left turn/stop and light green = back up lights. The light housings are grounded through the body. Im trying to remember how the floor shift manual trucks got the the power through the switch but its eluding me at the moment.