we own a vy calais and are having problems fixing the air con. a auto electrician could not fix it & our mechanic only fixed it momentarily. Took it to Holden dealer who described the fault as follows and wants around $1200 to fix -" found clutch not engaging - checked for power and earth at compressor - no power and earth - traced wiring via diagrams found ecu side of ground circuit not grounding - checked operation of clutch via tech ll ok - found communication problem between HVAC control panel & bcm - any ideas - Borneo