Truck problem

So who on here is an automotive guru? Ive got a small problem with my truck. A little while ago we had a bunch of freezing rain then it started to melt then it froze over again. Well that morning i went out to star my truck and she fired up just fine. The wile i was waiting for it to warm up i started cleaning the ice off and did the wind shield then cleaned off the wipers and the wipers pivot point. Then after i cleaned the rest of the ice off i got in my truck and noticed that the last time i drove it i left the wipers on. And i tried turning them off then back on again and nothing. Then i got out again to make sure ALL the ice was gone and it was i cleaned all of it off. So i figured i stripped the gears or something. So i started looking at everything i could see and played with the switch again. And found that the wipers work when their on full blast. As fast as they will go but not on the otter settings. So i know its an electrical problem. Maybe the switch. I tried googling it but google thinks i should refill the wiper fluid. Stupid google. Is there any way I can fix this? Id much rather do it myself than pay someone else to do it. Maby take the switch apart and clean the contacts? Im not sure.

Check you fuse, then check your relay, and then your switch. Most likely its something there thats burnt out

-edit- What kind of truck is it?

Would it be the fuse even thought it works on high? Amd its a 1999 GMC sierra 1500 with the 4.8 L V8. And just for the record its got over 234000 miles on it.

I just checked the fuse it fine. Im gonna try to open the panel. To look at the gear box.

It’s possible that it could be the switch. And it’s odd that they work when on the highest setting but not the others. I wonder is a connection in the wiring could be lose.

Its possible i googled how to get inside this thing. And it looks like its gonna be a bit of a pain. But man id so much rather fix this myself.