A/C and ECM Question

[LuLu]

Hello all. Wanted to say thanks for adding me. Also need some help....
A/C not blowing cold air after recharge. Repair shop says compressor and clutch are not getting signal to engage/run.
Heater works good
Can this diagnosis be correct?

 

[Scottydoggs]

the green wire off the compressor is the signal wire, make sure its not damaged. if you put 12 volts to it the compressor should engage. that green wire in most cars leads to the high pressure switch, pass side on the firewall at that round thing is a pipe off it. sensor is in the pipe. lol wish i knew all the proper names. but that pressure switch can fail and not send a signal.

 

[Doubeleive]

if you have the digital ac controls the control is known to take a crap usually they slowly die by working sometimes and not others or may have to be turned off and then back to make it work or you may have to shut the truck off and then restart, will blow hot only, etc if that has been happening then it's likely the control.