Low Pressure Too Low & High Pressure Normal or Too High

Test Results
1. Air at center vent nozzle cool but not cold.
2. Severe condensation or icing on inlet line of expansion valve.

Cause
Defective expansion valve is obstructing flow of refrigerant to evaporator.

Correction
1. Grasp expansion valve and, if it is too cold, proceed as follows:
a. Run A/C system at maximum cooling.
b. Spray expansion valve with refrigerant from aerosol can.
c. Observe low pressure reading, which should show increased vacuum.
2. If there is severe condensation or icing on expansion valve on inlet side, proceed as follows:
a. Drain A/C system.
b. Replace expansion valve.
c. Evacuate and fill A/C system.
d. Perform operational test.