It's not the motor or the resistor or the fuses. All check good. It was working fine and I turned it from Hi to Lo and it quit working on every setting. Sometimes it would come on first thing in the morning or while just driving down the road and work for a few minutes on HI only, then quit. If you turned it from HI to Med and then back to HI, it would not work again. Now is totally out. I'm I down to the switch or is there anything else to check?

 

Should mention it's a 2001 Chevy Express, with the solid state resistor and you have to modify the firewall to install a new resistor which no parts stores know about. Anybody know where to get the solid state resistor?