[Yukon Jack]

Go to the FAQ section and there is an index that contains a link to wiring diagrams.

I hate wiring/light problems! There should be a engine block to frame ground and then a number of grounds from the body to the frame in various locations. I'd make sure the bulb sockets are clean by hitting them with a little sand paper. I've got a short somewhere in my system that I can't locate and I'm about ready to buy new harnesses and start fresh!