A/C Controls

[ROLLTIDE72]

Can someone tell me how the Temperature control know works. I know someone is going to say "Turn the knob" But what i mean is how does it work. I tunred it to hot tonight and it only blew luke warm so i turned it to cold and it did not change. well after about 30 min of turn it back and forth and trying diferent vent it started to work fine. The fan controll worked the whoel time and the vent selector worked fine. Any ideas as to what happen and what i might look for if it does it again.

[NYMustang50]

heater core is clogged maybe..

[alberta 7.3]

The knob type uses a potentiometer on the knob, The actuator motor has a built-in module to control position. Sometimes the actuator units crap out. Happened to me in a late-90's E150, 35 below, and the dang thing was blowing cold air!!