我的情況是:AC light on, (no blinking), but no clutch engagement, thought was clutch/compressor problem, and gave up the repair about two year ago. This time using jumper (as 追風 mentioned) discovered that the clutch/compressor run, so must be low pressure or pressure switch problem.
X88: thanks for the step by step instructions. The AC system never been opened, still refrigerant left, can I still use vacuum pump?
Moonrivertttt: I did trying to charge with a left-over half can of r134s without compressor running, but it was not able to go in? I will get a new can to try again. The system hadn’t opened, but since there is no pressure difference between refrigerant can and the low port, how the refrigerant can be charged in?
Smallblack: agreed what you said.