Some may scoff at this, but here is how I fixed my headlight combo switch.
My low beams didn't work when I bought the car, and I traced the problem to a faulty combo switch. I was shocked to see that new switches are $400.00, and that the switch isn't even available for my 1988 Graduate.
I read some of the posts on this board about disassembling the switch and fixing it, but to be honest I just didn't feel like going through all that work, especially knowing that that if I broke something I couldn't buy a replacement.
Anyway, here is my current solution. I bypassed the combo switch with a toggle switch.
I located an empty spade connector on the back side of the fuse block that fed both headlights
I used a crimp connector and a piece of 12 gage wire and connected it to the open spade lug:
Then I mounted a switch using a fabricated bracket and the screw that holds on the cowling:
The circuit goes from the spade lug through the switch then to a power source.
Some might think this is cheesy, but the pros are:
No wires were cut, no holes were drilled, so everything can be undone at a later time if I want to do something different.
It works great and I'm happy with it.
Finally, thanks to PapaJam for his GREAT wiring diagram !!!