Ac clutch not getting 12 volts.

[Stone0928]

Hi my compressor clutch is not engaging. I checked the low pressure switch and 12v there I then checked the high pressure switch and there was 12v there too. I’m not getting any power to the clutch. im leaning towards ccrm. Any help?
Car is a 99 gt

 

[NXcoupe]

It is NOT your ccrm because you have 12V at both switches. Unplug the low pressure switch and use a paperclip to bypass the swich by inserting into the 2 plug cavities, this connects the 2 wires and will allow 12V to reach the compressor. Sounds like your ac system is low on refrigerant.

 

[giddyup306]

Jumpering the pressure switch is a BAD idea! The switches are there for a reason! Hook up a manifold gauge and see what the pressures actually are! Old (as in old for R12) had the same fitting for the low and high pressure side. People tried charging the high side, and cans would blow up in their hands!

 

[tsemmett]

Agreed, jumpering the switch is a bad idea; you can easily run the compressor without oil (as the refrigerant charge distributes oil).

You said you have 12V across the pins of both pressure switches but not at the clutch? Typically, the ground for that circuit is on the other side of the clutch from the switches; without the clutch connected, it shouldn't complete the circuit at the switches.

I'd definitely get a set of gauges on it and confirm the pressures, but also look at the clutch itself. You can measure resistance across the clutch pins (should be something like 3-6 ohms), and look for damage to the clutch hub (if the gap between the hub and coil were too large, the clutch wouldn't engage). You could also apply 12V to the coil to see if it engages.