OK, so since I purchased my 89 XJ the dash lights were very touchy, the dimmer itself didn't work but you could hit just the right spot and everything would light up. Also the front marker/turn lamps (the ones under the headlights) do not light up when the lights are on, but do illuminate when the turn signal or flashers are on.

Replaced headlight switch today with new one. Plug on headlight switch partially melted and some of the contacts both harness and switch side rather crusty. Cleaned up the connections on the plug and was able to get everything to seat properly to the new switch. headlights, Dash lights/dimmer works perfectly but still no marker/turn lamps!!

The bulbs are good, all fuses checked and I do have power at the socket. What's next? Start chasing the wires back to the fuse box? UGH I'd hate to do that lol.

Both the turn signal indicators on the cluster are lit with the lights on, but flash normally with the signals if that helps.

 

I suggest unplugging EVERY electrical connection in the engine bay you can find, whether engine related or not, and spraying it out with a good electronics cleaner, visually inspecting the terminals making sure they haven’t retracted into the plastic holder, and then plugging it back together. There’s a critical 10-pin connector for the front lighting system located in front of the air cleaner and behind the left headlight assembly. Don’t miss that one. Also be sure that the connectors to the ballast resistor mounted near the air cleaner housing are clean and tight.
ALL of the relays should be removed, the terminals wire-brushed until shiny, and the receptacles sprayed out with contact cleaner. Then plug them back in. I do this on every Renix Jeep I purchase or work on for someone else.
Revised 07/23/2012

 

Thanks. Narrowed down the problem to the sockets themselves.