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OK, this is my last hope. Summer is here. The a/c compressor went out in our 1995 C2500 Extcab Sierra pickup, 5.7L 350. We replaced the compressor, accumulator, condenser, hoses, o-rings, orifice tube, and the climate control. We have spent a lot of money and have been through hell with this thing. Well, the clutch is not turning on the brand new compressor!!! What the heck? Any help? PLEASE!!!

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If you have checked or replaced all mechanicals (with new parts) and refrigerant. The only thing left IS power.


Agreed. I am no AC expert, but I've fixed three of these systems by replacing the low pressure cut-off switch on the accumulator. Pull the connector and jump the contacts with a wire. If the clutch engages, check your pressures with manifold gauges. If the numbers are good, replace the switch. If the refrigerant is low, there's your problem. Check for leaks and re-charge.


If you pull the connector and jump it with a wire and the clutch doesn't engage, you have a power issue.

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I am getting a 96 going again. for those years something called a "thermocoupler" on brand new compressors might not be going right.

that goes on into 2003 apparently. Hit or miss.


if you still have your old compressor, could swap stuff around onto the new one.


you did not mention high side or low side valve. sometimes those pee a little leak to full drain.

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