[repairman54]

When system is off the pressures equalize both sides.
Turn on a/c and see if compressor clutch engages and watch the pressures. If low side drops below 20-25 it will shut off compressor to protect the system. It will re-engage when low side rises up to around 35-40 as pressures equalize.
Since you have 100 in the system check for comp. clutch engagement when equalized, if not then power check at compressor relay would be my first step. Relay swapping with the same size relay is a quick relay check.

 

[repairman54]

Yep looks like clutch is slipping by what looks like in the pictures of melted rubber dampeners.
Trouble is a JY one would need to be low mileage one. The clutch is a wear item and and as air gap increases in the clutch the less ''pull'' the magnet has to keep it engaged fully so they start slipping.
Clutch air gap info. - Measure the air gap between the pulley and the drive plate. Adjust the shims to achieve a 0.30-0.60 mm (0.011-0.023 in) air gap.

 

[repairman54]

With it jumped and running are your pressures good on the high side and low side and cold air good? That would confirm compressor is good and with clutch engaging harness to clutch is good.
Need to check for power to the relays engagement coil at the fuse block.
If none then high pressure cut off bad is possible or HVAC module is not sending power to the relay.
I don't have a schematic for yours as you will need it to track down why relay has no power to it's coil.

 

[repairman54]

Clutch engaged, center bolt turning then compressor is bad with no rise in high side or drop in low side.
System most likely will need to be flushed and new accumulator and orifice along with the compressor.

 

[repairman54]

It's either a high- or low-pressure sensor most likely. I don't have a schematic for your vehicle to check.