Testing and diagnosing a variable displacement A/C system compressor using the Robinair EVDC100

[@deanslegos1990]

Thank you for this information. Nobody else would have given this to me or known it themselves

[@fr0sty1998]

I have problem with my bmw e90 320d 2005 a/c system. When i turn on ac in the car only hot air comes out of the vents and a/c valve doesnt engage. But when i use ista+ and activate compressor valve for a second i se changes in pressure and cold air blows. What could be the issue?

[@smokeysmith1282]

So, the obvious follow up on my part is to determine when variable load compressors became a item and if my 2022 RAM is outfitted with this new technology.

[@JK-re5jr]

This tool is a waste of money and effort. Shops generally do not replace compressor electronic control valves. If a/c pressures are static with compressor clutch engaged, and a/c system is fully charged, check for battery voltage at control valve and computer controlled ground (variable voltage) on the other leg. With confirmed voltages, customer gets a new compressor and receiver/drier. Replacing just the solenoid is come-back city when the compressor fails, a pissed-off customer, and lost money.

[@mrashad219]

If you can see the shaft of the compressor turning doesn't that mean the compressor is working. Doesn't that mean the system has enough refrigerant and the clutch is engaging.?