Sorry but you may be wrong. When mine was tested and re-filled there were no faults, mine was empty but once filled did not start. I doubt it is the valves. Try taking a feed from a live straight to the compressor. If this fires up the compressor and you get cold air you have a full system. Next check for the relay , ignore the position of the relay , look for the white base. Try swapping relays ? Check for the voltage switch using a multi tester. Assume your cigarette lighter works ? This shares the Aircon fuse.