Auto Air Conditioning & Heater Repair: 94 Chevy Suburban Heater Control, chevy suburban, foot positions

Question
Hi hope you can help
The heater control on the dash has power and lights up but is permanently set to cold and none of the buttons on it do anything.
Should I replace the heater control?
Or is it something else.
Thanks

Answer
HI Dave

If you move the control does it change blower speeds and does it move the position the air is blowing.  In other word do you have control of the defrost panel and foot positions.  Let me know and I'll help.  Do you have rear heat and does it work.