Originally Posted by lifetime62
what if i don't have a harness on the passenger side
how would wire it up yhrn since it works off of ground
You can make your own harness as it only requires one wire.
The dome light doesn't care how many ground switches are connected to it. All it takes is one to become grounded and the light will light up.
Run an 18 gauge white wire from the new passenger door jamb pin switch over to the white wire on the driver's side. Now if either switch becomes grounded the dome light will work. If you cannot get to the driver's side pin switch wire, tap into it at the headlight switch.