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2015 silverado variable displacement compressor

Posted: Tue Oct 29, 2019 1:52 pm
by grumpy old man
I just finished an L83 and 6L80E swap into my '63 Pontiac. I am trying to get the A/C working. Everything on the system is off of the truck, compressor. condenser, evaporator and hoses. Obviously I do not have the BCM to control the de-stroking of the compressor so I added a low pressure cutoff and plan to cycle the clutch to control temp. Problem is that I started to charge the system and the low pressure is 75 pounds with 12 oz of R134 in the system which in my mind means that the compressor is de-stroked. My assumption was that the compressor would de-stroke by adding power so I don't have those wires connected. Does the compressor de-stroke by reducing power? If so would I feed 12 v to the de-stroking solenoid to get the compressor to maximum stroke? If not is there another way to disable the de-stroking system.

Re: 2015 silverado variable displacement compressor

Posted: Fri Nov 01, 2019 9:41 pm
by JohnHere
Voltage applied to the control-valve solenoid on a variable displacement compressor (VDC) is electronically varied according to the amount of cooling demand placed on the A/C system. So to answer your last two questions, yes, a VDC de-strokes and reduces displacement and capacity by reducing voltage to the solenoid. If you increase voltage to the solenoid and apply 12 to 13 volts (full battery voltage) to it, then the VDC will produce full displacement, full capacity, and the normally expected high-side and low-side pressures.