Ok so it’s a 2001 GMC Yukon xl 1500 slt. It’s got the temperature controls with the degrees in farenheit and rear defrost button on the control head/module. I have ice cold ac but I have no heat and no other vents blowing air. Meaning if I change it to defrost the windshield or blow air at my feet it laughs at me and says no. I’d rather not throw parts at it since Christmas is around the corner. Could you guide me to testing the controls and checking the actuators and identifying them or even a chart to which 1 is which. Thanks in advance for any help sparky.
I recommend performing a system recalibration.
Starting with the ignition off. Remove the Radio fuse for at least one full minute.
Re install the Radio fuse.
Turn the ignition on and wait 4 full minutes. Do Not Touch anything during this time.
Turn the ignition off for at least 10 seconds but no more than 30 seconds.
Start the engine and check the HVAC operation to see if the condition is corrected.
Ok I pulled the fuse waited 2 minutes reinstalled it and turned my ignition switch to the on position waited for 4 minutes turned on the truck and still no heat or different vents on the front.