Perform the following steps in order to determine whether or not the air conditioning, electrical, vacuum and refrigeration systems are operating properly:

1. Operation of the air conditioning blower at all 4 speeds with the mode lever in any position except OFF and engagement of the compressor clutch indicates that the electrical circuits are functioning properly.

The blower does not operate in any speed with the mode lever in the OFF position.

2. The same HAND-FELT temperature of the evaporator inlet pipe and the accumulator surface of an operating system indicates a properly charged system.
3. Operation of the heater and A/C mode lever in order to distribute air from the appropriate outlets indicates proper operation.

The system defaults to air flow in several modes if a vacuum system malfunction exists.