1970 Cuda,

Strange thing happened last night. I took my car to a show, on the way home I was told my rear lights where out (running/brake/turn signals), I pulled over to check things out. Nothing seemed out of the ordinary, (lose wire/ground) looked at the fuses, everything okay. I jump back in and try the light switch, then moved the dimmer switch, dash lights went out, now I am scathing my head. Got out checked the tail lights, everything working back there but no dash lights. I decide to drive it home. Today I go over everything, power to the dash lights, dimmer switch but still no dash lights. Did the dimmer switch cause the tail lights to fail? I think I need to replace the switch?

Is there something I am missing.