Check the wiring schematics. If you know what color ground your car typacally uses (most on mine are brown colored), I plan on gator-clipping to that post on the light socket, and attaching it to a known ground. If that cures it, it's the ground. The thing that I'm having trouble with is the fact that if the system isn't right, it will quik-flash as if there is no bulb. That's where my fun is.

__________________
1989 300E 144K