After doing some searching I havent found a good answer to my problem. My 94 5.7 ac clutch keeps engaging and disengaging about every 3 sec when the air is on. I can feel the eng load while driving when this happens. I have decent cold air flow, the clutch has a little grind when it engages but not bad for 150000 mi.

Thank you for any help
Rob

The system is designed to cycle but in your case it is cycling too much. You can be low on r134a or the pressure cycling switch is bad causing it to cycle too much.

You need to put some gauges on it and watch what the low side is doing. Normally, the compressor comes on around 44 PSI and will stay on until it gets to 21 PSI. The compressor will stay off until 44 PSI again.

If you see the compressor cycling at the right pressures, you are probably low on r134a.

//2000CAYukon