Whats up guys. New to this place. My AC works. blows cold. problem is.. switch doesnt do anything with speed or off.. the direction works. as well as the tempature but speed does not. when i sit still it doesnt blow. when i drive it blow on high and cant turn it down. any ideas?

was told it was the AC clutch . but understand that only tells when the compressor to turn on and off.??

the vehicle is a 99 chevy k3500 srw CC 4wd.

 

You are correct, it is not the clutch. Sounds like it is the switch and or the fan motor resistor.

 

I was thinking switch also. Im gonna try that fist.