The headlight switch is attached to the knob that operates the headlights, in the dash. Its a bitch to change.
I think you are probably not getting voltage through to the headlight switch then. Probably not a switch problem. You will have to find that wire that should be on the starter battery post that I mentioned earlier. That fusable link may have blown.
Read my last post, I dont think its a switch problem. I thought they came on & faded every time you turned the lights on. Because they dont, I doubt its the switch.
ITs not like your used to seeing. What it will be is a thick wire with a big ring terminal that usually bolts on the solenoid post. It may be bolted to other wires and just insulated. Thats usually what happens when an amp gauge is installed. Directly behind the ring terminal, the wire will be real thick, more than twice the diameter of the wire. That is the fuse part. If you have a volt/ohm meter, its pretty easy to test it.