Jeff,
I am Danish. Our heads are small and somewhat flat so we have a better time getting under the dash to look at stuff. My problem is the neck. My neck gets real sore from holding up my head.
Is your switch one of the red ones that clamp to the bottom of your dash? That is the one I had. It has a red plastic front, a ceramic backing with a spiral wire that the electricity goes through. As you turned the front knob the lever went across the spiral wire and the fan moved faster. That thing gets real hot.
So, I put this problem on this website and it was recommended that I buy one of the old switches. I found one on ebay and payed about $20 for it. I think it is a GMC switch. It is two speed and has coils sticking out the back. They are probably for cooling purposes. It works great and I suggest you go that route.
As for the rest of you electronical folks. I did not understand what you were discussing but in my simpleton way I appreciated your help with my problem. Thank you.
I hope this helped.