The Robinair Electronic Variable Compressor Tester, No. EVDC100, enables technicians to quickly test electronic control valves in variable displacement compressors to determine if functioning correctly and eliminating compressor misdiagnosis. The EVDC100 works by varying voltage supplied to the refrigerant control valve on the compressor to verify valve function, mimicking a properly functioning compressor valve for a quick and accurate diagnosis. It’s designed to work with multiple variable displacement compressors. Powered by the vehicle’s battery, the tester’s connector adapters work on both old and newer style compressors and include heavy duty battery clips. It also includes a 6' wiring harness and removable cable assemblies for easy replacement.