Originally Posted by pwogaman

Some OE headlight switches are worse than others. I have had a number go bad, essentially the plastic material inside crumbles and gets in the way of the contacts. In every case the switch has been the light colored exterior, and never one with a black exterior. Whenever I grab a switch at a pick and pull I give it a good shake first. If you shake it and can hear bits rattling around it is toast.

Originally Posted by Mxfrank

Good news! Your headlamp switch is almost certainly ok. Bad news! You may have a bad turn signal switch.

The only easy out would be if both headlight sockets have failed...you can check for power at the sockets by pushing a pin into the insulation of the low beam wire, and checking for power between the pin and ground.