Hello, been lurking and reading for a while, but this is my first post. Been trying to figure out an ac issue. Air blow cool, not cold and ever now and then the engine will try to stall out and there is a rattle that is only there when the ac is on . I checked the bearing on the pully, it looks good. The clutch engages and disengage with the switch. Servicing looks to be good. I'm leaning toward the compressor. Thought I would see if anyone else has anything else to try before I go that route. Thanks for any and all advice.

 

Welcome to the forum

Well the compressor is what makes it cold and the only "moving" part in the system, so only thing that could cause a rattle.

AC and refrigerators/freezers all work the same way
Compress a liquid and it heats up
Decompress a liquid and it cools down

Grab a spray can with compressed air inside and release some of that pressure, can starts to get cold, decompressing cools it down

So if your compressor is not increasing the pressure(compressing) like it once did then cooling wouldn't be like it once was.
Same if system is low on fluid, less fluid less compression so less cooling.