70 Charger headlight switch repair?

[RTDaddy]

Have headlights, but no marker lights.  Jumping across the plug terminals gets marker lights, and voltmeter shows no continuity through switch for markers, so I figure bad switch.  Headlights do operate, and switch shows continuity in that position.  Took an old spare switch apart and these things look relatively simple.  Cleaned the contacts, polished out pitting, stretched the springs for the contacts to insure good contact with terminal plates, but still cannot get continuity to the markers.  Anyone else been down this road?

"IF YOU'RE UNDER CONTROL, YOU AIN'T GOING FAST ENOUGH."

[AKcharger]

Hey big daddy

If I were a bettin' man I'd say you are loosing a ground to corrosion. I'd put all your efforts in that direction. I know about 97% of all my '70 & '72 electrical problems have been ground related

[Nacho-RT74]

I can't recall right now on 2nd gens ( would have to check later for diagrams ) but at least on 3rd gens, the headlights switch gets TWO DIFF INPUTS, one to feed just the headlights, directly from batt and the other one to feed parking and cluster lights, coming from fuseblock.

maybe that would be something to check, one input not coming in to the switch