First do the AC controls have rotary knobs to control the temperature and air flow? Or do you have an electronic control panel? See image 1+2 below.
If you have the rotary control knobs then the activation for the heat distribution is done via cables, no electronic actuators would be involved.
I would suggest first having the level of the refrigerant checked before any other repairs are carried out.
If the refrigerant in the A/C system is low, then the compressor will not engage.
Low refrigerant can be caused by a leak in the A/C system.
See a good article:
Images (Click to enlarge)
Tuesday, February 21st, 2023 AT 9:36 AM