Is a/c and central locking system on the same vacuum system? The reason I asked is that they both stopped working. I took the car to the dealer a couple of years ago and had the a/c converted to R134. The car cooled wonderfully that summer and last summer. When I tried to use the a/c the other day, it didn't respond when I turned the a/c button to the on position and switched it to max a/c on the control panel. Also the central locking system is malfunctioning. When I lock the driver's side door, the other locks do not lock i.e, the trunk,the fuel tank,and passenger door. The car is a 79 300cd. Please help because I really need my a/c soon.