When headlamp swith is in the auto position, lights come on at dark and work correctly. When switch is in the manual position all instrument and running lights except for low beams work. High beam operates in the manual position.

 

Maybe try checking out the wiring schematic in the back of the Haynes Maintenance manual, they have helped me in the past. In the schematic locate each part of the lights wiring system (find out what each part controls), then break it down as to which of the circuits are working and maybe you'll find your problem. If you're not good with a schematic maybe you know somebody. Good luck. Let us know what you find.