1990 heater control inop??

[Hoyt572]

I'm working on a 1990 chevy for a friend, It has the electric heater control head, the screen on it shows one of the little arrows on it but that is all, so it does have power, but none of the controls on it do anything, and the blower motor in the truck is constantly on, I'd say somewhere between medium and high. any thoughts?? Thanks

 

[SwampNasty]

You'll more than likely have to replace the whole unit, just take the four dash screws out and unbolt it from the dash. Then it's a matter of unplugging it and replacing.