Check for power on the inside of the cab, at the plug.
Check for power on the inside of the engine bay, at the plug.
Check to see if the harness runs from the firewall plug to the rear of the truck.
Check to see if the wiring or insulation has been compromised, throughout the length of the harness, to avoid any electrical mishaps.
If the wiring is there, great...if it is not, install it to the rear lights...yellow, brown, white, light green & dark green (reverse)
