Charged A.C. System Not Working

[Jet]

This is on my '97 W-body Regal. A.C. blowing hot air, clutch on compressor isn't turning. I bought a can of R-134a that came with its' own little gauge; when I put the gauge on the low-pressure port, it shows to be adequately charged. Swapped the fuses/relays in the fusebox with others, no change (like it would be something so simple for me). Scanned the lines throughtout the underhood system, and there is no low-pressure switch, or any switch that I can see that might be the culprit. I know if a system is low, they have switches that won't allow the compressor to come on to save the equipment, but if the system shows to be fully charged, well, WTF?

[Oklahoma]

Have you checked the electrical connection to the compressor clutch? If it's not getting power, the inner pulley won't engage. It's just a small wire that goes straight to the front of the compressor.

[Prospeeder]

it HAS To have a low pressure switch. It also has a high pressure switch, if either have failed, it wont allow the system to come on. Try jumpering each of them to see if they come on. Low side usually on the acumulator/line going to or from acuumulator. And the High switch is either on the compressor itself or one of the smaller high side lines.

[86euro]

Also, that gauge is only for use when the compressor is running. If it's showing in the good area without the compressor actually running, the system is still very low.

[dcjredline]

Prospeeder has got it. I have a flaky connection on my Formulas Low pressure switch.

[Jet]

And the winner is...Oklahoma. The two pins on the front of the compressor connector were pinched in towards each other, and not making contact with the wiring harness connector. But, now the blend system is screwed, cuz I am getting 60 degree air from the passenger's side vents, and ambient (90+ degree air) out of the driver's side. This is a common problem with the W-bodys, requiring an actuator to be replaced.

[Prospeeder]

meh yea usually a blend door sticks. theres a way to pull codes from the HVAC system on those newer cars, i just am not sure how.

[Jr's3800]

If the car has dual zone climate control its possible for the drivers side to have a bad Temp control actuator..

[turbokinetic]

Some of the newer cars have a pressure transducer on the compressor high pressure side instead of the switches. The ECM uses this for low charge, over-pressure, and cooling fan control. Not sure if yours has it but figured I'd throw that out there!
David