I've got a 93 blazer, when I turn the headlights on my dash lights go out, my oil pressure gauage goes to 0, my thermostat gauage goes to 260plus, my fuel Guage goes to empty, my turn singlevlights turn and stay on but don't blink, unless activated to do so, and high beam indicator comes on, I read a few forms indicating it may be just the headlight switch, all lights come on and are functional!!! Is this just the switch??