'91 Silverado, 5.7L V8 Is it possible for the switch to go bad in a way that will turn on the parking lights, but not complete the cicuit for the headlamps? My headlamps will not come on. Parking lights are fine. I checked the fuses and they are good. The ground on the fender well behind the battery is good, and I even tightened him down. The headlamps did come on briefly. I pulled into Adv. Auto to pick up some relays (thinking they were bad), tested the headlights and they came on. So I left and by the time I drove a mile down the road to my office, they no longer came on. The dome light works, and the instrument panel lights work. Only the headlights don't come on. So I am thinking faulty light switch. Good place to start?