When I use my A/C or heater, my #1 switch doesn't work. What's up. Does it need a little WD-40. #2,3 & 4 work good. Should I sell my truck, or should I rip the dash apart. (Fan control switch)

your blower resistor is bad

I was looking in my book and that makes sense according to the schematic. Is there a different resistor for each switch value? The book doesn't say were to find this resistor. Is it somewhere behind the glove box or on the blower. Can I replace just the affected resistor or is this like an enclosed unit. Thanks.

The resistor is all one unit it is on the blower case in the very back of it