No power to compressor

[81Regal]

Heres a couple of pics from my 87 Cutlass, dont mind the mess its been a while since Ive had it out.

 

[xcookpac]

My suggestions for analyzing this issue are as follows:

1. Test operation of 25A fuse for A/C (shown at top of drawing);

2. Assuming 25A fuse is good, turn A/C to normal and fan to medium, or high, then measure voltage at light green wire at the pressure cycling switch connector (my guess is you have no power here).

3. Assuming light green wire has power coming into pressure cycling switch connector, then continue with A/C on and fan to medium, or high, THEN measure voltage at DARK green wire (at the pressure cycling switch connector).

4. Measure voltage on dark green wire at A/C compressor.

5. Measure voltage difference between black wire at A/C compressor and battery ground.

Report back with your findings.

 

[xcookpac]

FYI

C127 connector schematic and pic.

 

[Gary Willard]

Please help me analyze this.... My car was taken off the computer before i bought it and is still running on the original block and transmission after mods made. The AC has never worked and now i want it to. Ive done the system conversion to R134a. Flushed condensor & evaporator, replaced accumulator and low pressure switch, new orings, vaccuum check and tried to charge the system with gauges. I have good fuse and contnuity at the switch. Clutch will engage with direct voltage, but it is not getting voltage from the pressure switch side. What could my problem be? A switch bypass does nothing, so i have an issue between switch connection and the compressor. Did removing the computer cause an issue I don’t know about?

Sorry guys.... I’m dealing with my 84’ Hurst Olds. Also.... the fan switch high setting doesn’t work either. I was guessing it was the actual switch, but it sounds like it could be in the relay? I’ll fix that after i get the compressor to turn on.