Can anyone help me out with the issue I'm having. I just replaced my compressor and evacuated the system. Now I'm trying to fill the system up with R134a. Conderser fan comes on and got 57 psi in the system and the clutch will not engage. What can be the cause of this? I tested the relays shot the wires from B2(yel from EMC to the relay. Also I have 12vdc sitting on the positive side of the relay coil. Also, had 12vdc on the white wire to the relay contact and shot the output red wire going to the compressor wire. Also, tested the clutch coil on the compressor and all checked good. Its looking like the yellow wire from the ECM is not providing a ground. What can be the cause. When does the yellow wire sends the ground to the relay to energize it to close the contacts and send 12vdc from the white wire to the red wire that connects to the compressor. Any help will be welcome. Thans.

Mike

 

Is your pressure switch on your high pressure line connected? It's right near the lower radiator hose connection at the radiator.

 

for test purposes only - Short the wires in the pressure sensor connector and see if the compressor comes on.