If you are getting power into the switch (obvious by other stuff working) but not getting power out of the switch then I sounds like the switch to me. Testing the wire at the switch eliminates the rest of the wiring back to the bulb and the ground, if no power then it's in the switch (again, provided you are getting power into the switch), if power then the troubles are down the line. I have seen what X is talking about with both the ground issue and with the "normal"switch activation position not making contact and other areas in the sweep making contact. The switch being loose (the 2 halfs not tightly connected through the swing or corrosion on the contacts inside the switch either one can cause a single side issue, it could also be that one of the contacts inside the switch has jsut fallen off. We are talking about ancient switches on most of these things, pull the steering wheel and do some looking, poking and pushing, you'll find it.