A/C idle up not working

I get no cool air when the a/c is on at idle; there doesn't seem to be any increase in RPM when turning on the a/c. From what I can gather the '01 3.4L idle increase is done by the ECM so I'm assuming the issue is in the signal from the a/c controls in the dash to the ECM. Is there a diagnostic process for checking this?

 

On further investigation, the compressor clutch only engages when I open the throttle - at idle it's disengaged.

 

Bump, hoping somebody can point me in the right direction because I'm at my wits end on this and sweating in traffic.

 

I would check your freon with some gauges and go from there.

 

If you turn on your truck parked and turn on the air conditioning it won’t engage at all until you start driving?

 

it may be a low-pressure situation that's causing the system not to cycle on. you may just need a top-off of refrigerant.

 

Never heard of the AC clutch disable at idle before, idle up, yes, my 96 has one for the power steering. Other than the throttle position sensor sending a signal to the PCM to enable/disable I cant think of any other sensor on the motor or the AC system that would know idle or not.

 

The A/C light turns on on the dashboard when I turn the a/c fan dial up, but the clutch does not engage. With the hood up and the truck in park, I can grab the throttle and open it a tiny bit and the a/c clutch engages.

A friend of mine has gauges and has done A/C service before, next time I go over to his place to help with another friend's old Cougar project I'll bring some refrigerant and get him to help me test the pressure - thanks for the suggestion

 

My 95 2.7 has a VSV mounted on the valve cover, that idles the RPM up when your at a idle, and drops down in RPM when it's time to clutch cycle off and back on (cycling). It gets it's signal from the ECM by the way it acts.