scumpoozie

Hi, 2001. Has had a compressor replacement a few years ago. When I turn the A/C on, the compressor will engage and air will blow cold for a few seconds (10 or so) then compressor will disengage for 10 or so seconds. It cycles like this consistently. Any ideas? Thanks in advance.
2001 Silverado w/t 4.3l 333k miles (yes that's correct)

Monorail_Red

That's the way the compressor functions on my '12 Silverado and same went for my '04 Colorado that I traded in last year. It would run for a bit, then disengage, then start again. There is no real noticeable temperature change from the A/C ducts when this happens for me. A/C compressors would freeze up if they continuously ran without cycling as they do.

tech2

the system is short cycling due to low refridgerant levels. The pressure will drop so low in the low side that the low pressure switch trips and shuts down the a/c clutch. To confirm this have the system recovered. This is the only way to accuratly quantify refridgerant level.

cleveland63b

+1 probably low refrigerant

DoubleO7

and if it goes low enough, it won't engage the compressor clutch at all.

Fireair7215

sounds like low refrigerant to me. Make sure that evaporator is clean, air filter is clean, blower motor running ok. If all of it are ok, then its refrigerant issue. Injection dye and recharge.

99 Silverado 3 door

This may be a dumb response but aren't they supposed to turn on and off? If they ran all the time wouldn't they freeze up? When I was younger I had a car with air but the clutch wouldn't engage. I hooked up a toggle switch on the dash to run power to the A/C clutch. It sure cooled after that but after a while of constant running it would start blowing frost out the vents inside the car. That's why I believe they are supposed to turn on then off. That being said I would still check the coolant to make sure.

tech2

yes they should cycle. A 10 second cycle is way to frequent to be normally operation. I suspect, the low pressure switch is tripping, shutting down the system prematurely due to low r134a levels.