2012 Mack GU713 Granite Air Conditioner.

[David Bidelspach]

We are working on a 2012 Mack GU713 Granite.  The A/C Compressor does not start with the normal switch.  We checked the Switch on the Dash, and it is working properly.  If we provide Power to the A/C Compressor, the A/C Compressor does work, and Blows Cold.  It appears we have Power to the ECU, but no Power from the ECU to the A/C Compressor.  I am thinking there is a Sensor, that is telling the A/C Compressor not to turn on.  Any help is greatly appreciated.  Thank you.

[David Bidelspach]

Perhaps, it is the High Pressure Switch, Switch - Binary or Expansion Valve.  Again, any help would be greatly appreciated.  Thank you.

[David Bidelspach]

Then again, maybe the Freon is not at the proper level, too little or too much (Pressure).  My Mechanic says the Freon is correct.  I need to have him double check.  Thank you.

[ctonline]

On 2/1/2021 at 5:31 PM, David Bidelspach said:

Then again, maybe the Freon is not at the proper level, too little or too much (Pressure).  My Mechanic says the Freon is correct.  I need to have him double check.  Thank you.

So the high pressure is about at 200 psi & low pressure is about at 30 psi ?