1999 kw t800 a/c fan problem

I’m working on a 99 Kenworth right now but I just put a new blower motor and new speed control switch it seems like it’s working but when it’s in high Speed the wire that comes out of the switch becomes really hot any thoughts

 

Sounds like you're encountering resistance of some sort. Have you felt the plug which the MVAC blower itself plugs into? Ran into that this past Sunday, albeit on a shaker, where the terminal prongs were shorting and it was overheating the housing.

 

Know this is late, but the guy that had the fan kick out after 2 minutes. Then start back up after a minute. Mine was the relay for the ran motor. In the fuse box. It had gotten weak. And would get hot and kick out. Then cool off and let it run again.