Low Pressure Too High & High Pressure Reading High or Normal

Test Results
1. Center vent nozzle temperature too high.
2. Uneven compressor operation. Compressor vibrates.
3. Severe icing on refrigerant hose running from evaporator to compressor at compressor connection pipe.

Cause
Expansion valve is defective, resulting in excessive delivery of refrigerant.

Correction
1. Check expansion valve as follows:
a. Run A/C at maximum cooling; Fan Speed III, ``recirculated air'', engine at 1500-2000 RPM.
b. Spray expansion valve diaphragm with refrigerant from aerosol can.
c. Observe low pressure reading. If reading does not show vacuum, proceed to step 2.
2. Drain A/C system.
3. Replace expansion valve.
4. Evacuate and fill A/C system.
5. Perform operational test.