What were the pressures? Is your mechanic a qualified AC tech?

 

I think this is the thread greg8453 meant to post in.

 

p0128 no longer shows up since i changed the thermostat , car runs between 180-210 (did hit 214 but went down after that)
i''lll burp the system anyway to make sure.

 

and also yes, the person who checked is a qualified ac mechanic, if all else fails he said Monday i can go in and have his boss take a better look

 

I'm not sure about HHR's but GM does use the the strategy if the PCM this doesn't see at least 55 degrees it will not work.
I've fixed a couple of them. If they are open it reads -40
You know I'm not sure they had the display. Early ones used it for ECM input and no output for display to dash.

 

If you have the display and it's not to far off you are good. Needs to be at 55 or below to go into winter mode. In that mode it will still cycle at times just to keep the oil moving around.
Do you have the display for outside temperature?

 

display for outside reads,but, higher than the actual temp outside. so should be good?

 

You haven't said which thermostat was installed.

 

I'm pretty sure they do not use a separate sensor for each so yes that is fine.

 

HHR is the simple version of 21st century GM. It does not work like an Impala or Cadillac or a GM truck.
The ambient air temp sensor is mostly for the display. The MAF has a temp sensor in it for A/F calculations. The EngineCoolantTemperature sensor shows in the digital readout, the analog(useless) and is used by the BCM/ECM.
The Shop Manual does not mention ANY connection between Ambient air temp and the AC system There is a connection between the ECT and the AC system, as previously discussed.
If the digital ECT reading is all --- the AC compressor will not run. That is caused by a P0128 code and usually but not always a CheckEngineLight.
If
1.) the blend door is in the correct position and
2.) the compressor is engaged
it is not possible to be blowing warm air out the vents. The blend door controls how much heat is introduced to the air mixture. The normal air flow is from outside over the AC evaporator past the heater blend door into the cabin. You can adjust the temperature this way with the AC on.

My guess is that whoever is looking at the compressor doesn't know how it works or the blend door is stuck open.