It seems that I need to fix the car AC system, as a start, let me accumulate some videos.
8 possible reasons that clutch fails to engage, pretty thorough.
This guy shows the noise diagnosis and fixing on a car AC problem.
Replacing the 2007 Acura RDX AC compressor pulley
If one needs to replace the compressor, there are a few things to keep in mind
Make sure the compressor comes with "right amount" of oil, otherwise, we have to supply the oil like shown in this video
Make sure to get new O-rings for both high and low valve connection, use the oil to lubricate the O-rings properly
Get a manifold meter to monitor the AC system
Vacuum the system to -30 on the low side and wait for an hour to make sure it seals well. Then put on the vacuum for another 45 minutes
After connect to the refrigerant, make sure to purge the residual air/moister in the yellow feeding line.
Turn the AC on and fan on, start to fill the system until the compressor kicks on. Continue adding right amount of the refrigerant
