1976 Chevy Corvette All instrument lights went out

When the dash lites go out, do the tail-lamps go out also? They get voltage from the same fuse circuit. Does rotating the knob for the headlite switch cause any reaction to the dash lites?

You can check the wiring circuit from the headlite switch. The feed for I/P illumination is a dark green wire. You can also check the feed to the lite switch.

Tail lamps still work and all lights still work except the instrument lights. The rotating knob does not cause any reaction at all.

Now what could be the problem? What do I check next! Thanks, Jeff

You need to get at the wiring circuit for the lite switch, check the feed circuit to the instrument cluster, dark green wire.