If the compressor failed internally it could be calling for AC and turning on the clutch but the compressor isn't really working. The thing is that if it is internal failure you will likely need to replace more than just the compressor. When they fail they tend to spit fragments out that travel in the lines and condenser and cause blockages. The normal process is to verify the compressor failure and then remove the parts and flush the system then replace the compressor, condenser, drier, expansion valve and the seals and oil. That is to keep any debris from cycling into the new parts and causing a failure.
I attached a pic of the instructions that come with a new compressor. A kit with all those parts runs about $400.00 on RockAuto. Com depending on which compressor style you have. I would say you can DIY most of the parts but the front condenser isn't fun as VW made it's replacement very difficult without the correct tools. You have to remove most of the front of the car to get to it! The fenders and bumper come off as one piece, then you remove the radiator support, drain the cooling system and disconnect the radiator and tip the lock carrier out. Then you can remove the radiator and the condenser!
Now another approach if it is a bad compressor would be to get a used one, then remove the lines you can get to, flush the system a couple times in both directions, add half a charge of oil to the compressor turn it over a few times to be sure it works and install it. Charge the system with the rest of the oil and see if you have AC. Not the best way but I've seen it work.
All of those will require the refrigerant to be recovered and then once the parts are replaced you would need to pull a vacuum to remove anything left behind in the lines or drier. Then recharge the system by weight.
Thursday, July 11th, 2019 AT 2:32 PM