I have already replaced the ignition switch, headlight switch, turn signal switch, wiper motor switch and door jamb switches...

New harnesses, except for under dash. No apparent splices.

Engine grounded in 3 places. block to body, block to frame, block to frame to body. Battery ground to block and to pass fender. I too suspect a bad ground somewhere as it would also explain the rear running lights being able to be on when the light switch is in the off position, but by turning the dimmer they come on. The fronts do not.

I will have to check for bad ground for the lighting circuit. Any particular place recommended to start. Off the top of my head, I'm not sure where the specific ground wire for the lighting circuits are. I know most are picked up via the socket holders.

Could a bad printed circuit board cause such a problem? My ammeter does not work and I purchased one to see if that remedies that problem. Just have not gotten to that yet.

Thanks for the feedback so far.