HVAC Controls

In Sep 19 I had the AC system gone thru. This unit lasted 15 years. Compressor was starting to go and of course it spread all the debris throughout. About 11 months later the lights in the control unit started going out. No biggie took one out went to parts store ordered them and replaced. Then they did it again so I ordered a unit from Rock Auto. Installed and all is good. So I thought. Now my AC freezes up thinking I have another AC problem. Take it back again. He finds a shrader valve leaking . Freezes up again. The tech says either the probe behind the dash is bad or the HVAC Control unit. Thankfully I didn't throw the old one away. Fixed the lights in it again put it in all works awesome now. I was not wanting to pull the dash, but if did it was going to get the blend repair if it didnt need it. But I think maybe that HVAC Control may have caused some issues that are not happening now.

 

You said you had your system "Gone Through". Freeze up can be caused by the freeze switch in the AC evaporator being either placed in the wrong place or the switch is defective. Low charge can cause freeze up too but generally the freeze switch in the evap will cut out the compressor. Did you have the evaporator replaced? You can remove the glove box and look behind there and see if the freeze switch is hooked up. The label on the wire loom to it I believe says "Thermistor".
Our A/C control is pretty simple. My understanding is that the AC runs full bore all the time as far as the compressor is concerned. The compressor is governed by the freeze switch or Thermistor. You regulate the temp with either the fan switch or add heat with the temperature mixer knob.