ok so i went to charge my system in my garage using my cheap manifolds, but my ac clutch wouldnt engage. i ended up having the dealership i work for charge it up and the master mechanic there said that i had a ground problem, he said he believed it was the one that goes to the ac and heater controls, but i didnt feel like paying a shop rate to have a someone trace wires for me all day. i was wondering if anyone has ever had any similar problems and could give me any more advice, because ac systems just arent really my forte.

 

When the system is discharged, the low pressure switch opens and the compressor won't engage. This is to protect the compressor. When you charge an empty system, you can add refrigerant slowly until the compressor engages, or short out the pressure switch connection to bring the compressor on. As usual the system should be evacuated first to get rid of all moisture, and proper pressu gages should be used to prevent causing damage or poor performance.

 

yeah well it didnt matter when i bypassed the low pressure switch, plus now that the system is charged and it still doesnt engage the clutch

 

Check for voltage at the clutch, green wire. If there is voltage, thenthe clutch windings burned out. If no voltage, check fuse for clutch control relay (fuse #12 under hood), Also check fuse #3 in intrument panel fuse box. If fuses are OK, apply battery to green/white wire from relay. Relay should operate and clutch engage, if not check the relay and clutch windings.