I fixed my fan speed switch which was only giving me 1 and 2 speeds. 3 and 4 did not work. It took about 2 hours start to finish.

The switch is in two halves, top and bottom. Bottom has the copper contact bars brass riveted to housing half for all five positions. The slide (what you move back and forth to select speed with) has a copper shoe that is held down on the contact bars by a spring.

Over time because of the amperage the bars become warped and the shoe's spring weakens. Stretch the spring, clean the copper shoe and bars with 0000 steel wool until shiny, correct bars warp with large flat blade screw driver by pushing down on bars on a bench until the bottom half contacts bench. It's very easy, little pressure needed.

I connected my switch back to the multi-plug and viola', had all four speeds again. A dab of dielectric grease and good as new. If your handy there are a couple of other tweaks to make it last a long time.

So it's possible to fix the fan switch just like it is to fix the intermittent wipers when they don't park.

 

Mine cuts out periodically, mostly when the vehicle gets warmed up inside. Now I can dig in without being blind.

 

Mine was acting up while cold. Worked perfect in warm weather. Today it's 40 degrees and I decided I can't go any longer this winter without having high. It's acted up the entire four years I've had the truck. Finally I had it and was going to find out what could be done, if it could be fixed. Many old timers have said you need to buy the mix panel to get a new switch if you can even find one. Mondo expensive when found.

 

I see you mentioned wipers, have you done that aswitch as well?

 

Wiper motor has a nylon gear with a copper contact inlay. Again because of the high amperage the nylon will become soft and smear the contact inlay and pit the gear at the park position. Yes I fixed mine. Again it's a common issue and the old timers say the motor has to be replaced.

These trucks have many parts that are made well enough to be fixed if someone has the patience.

 

I recommend you take it all apart again to provide us with pictures. ;-)

I only have two speeds as well so this is encouraging...

 

I'm younger than you!!!

Very nice Scouts, very nice.
I need to clean mine up, number 2 cuts out sometimes on me, nothing like letting her warm up for 10 min only to go back out to leave for work and find the windows still frosted over. lol

 

You know, I should have but I didn't really think it was possible to fix it. Which two speeds do you have?

 

If I fiddled with the switch in position 3 it sometimes would come on.

Nothing like messing with the switch in 5 degree weather while the inside of the windscreen is freezing over because of my breath. Position 2 sucks.......

 

I only loose #2, but if I wiggle the switch it will come right back, that is the fan speed I use 98% of the time and I only loose it maybe once every 2 weeks so not a big deal.
One of those things I have on my to-do list but never do. lol