ac problems
Pro
Joined: Jun 2007
Posts: 631
Likes: 3
From: Joppa AL
I would also recommend checking the AC chg level. The PCM senses pressure in the system and shuts off the compressor if it is not within spec. As RPM increases, the low side goes lower and the high side goes higher. Either condition could cause compressor shut down. To verify if that is the case, watch the compressor clutch rotate at idle, have a buddy press on the gas pedal and see if the clutch stops turning at some eng speed. HTH
Pro
Joined: Sep 2007
Posts: 735
Likes: 7
From: Bucks County Pa
May be air doors
Hi, A couple of possibilities causing your problem. Is your unit set to inside recirculate, or outdoor mix. In very hot weather a unit set to outside air will tend to blow less cold when car is in motion. If it is set to recirculate, and blows warmer when in motion, your air mixture doors may not be operating properly. Possible faulty vacumn line, actuator, or debris jamming the door open. One other remote possibility is a faulty heater valve, when you are in motion (more rpm's), putting more pressure on the coolant from the water pump, it may be forcing more hot water into the mix than the temp settings are calling for, more or less overriding the temp settings. You could check the refridgerant charge, but normally with a shortage of refridgerant you will blow colder as the rpm's increase, up to the point that there is not enough refridgerant to actuate the pressure sensors. Hope any of this helps
Good Luck
Good Luck
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
I would also recommend checking the AC chg level. The PCM senses pressure in the system and shuts off the compressor if it is not within spec. As RPM increases, the low side goes lower and the high side goes higher. Either condition could cause compressor shut down. To verify if that is the case, watch the compressor clutch rotate at idle, have a buddy press on the gas pedal and see if the clutch stops turning at some eng speed. HTH
100% on the money!BC
Safety Car
Joined: Jan 2000
Posts: 3,902
Likes: 248
From: Orlando FL
Hmmm. Mine is doing the same thing, however it blows cold on the passenger side all of the time, but the drivers side is cold at an idle, then warms up when driving. Just installed a new compressor, orifice tube and filter, also a new control head. Weird, we checked the charge level and it is right on the specs. Mine does this when I first start it and seems to even out and work as it should, cold all of the time after driving for 25-20 minutes. I have been scratching my head over this one.
