Variable displacement compressors

Hello I had a 2007 Dodge Caliber with a 2.0L come in to my shop, the cus. Concern was that the a/c was not working. Hooked a scan tool up and saw that the a/c switch was working and that the duty cycle was at 95%, when to varify at the compressor but could not see any voltage going to the compressor. I guess my question is, how can you test voltage on a variable displacement compressor with out a scope.

Others may have a better answer but you can measure voltage with a dvom oscillations in voltage happen so fast your dvom will just read a percentage of battery Voltage for example at 12v a 50% duty cycle will read 6v on your dvom

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You should have been seeing around 12 volts at the compressor assuming charging voltage was aprox 13

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A lot of Digital meters will measure duty cycle, certainly the one I use the most the Owon B35T will and I am pretty sure some of my others do.