Jeep 1987 Wrangler Workshop Manual page 1024

HEATING AND AIR CONDITIONING
AIR CONDITIONING SYSTEM
DIAGNOSIS CHART C
I
Condition
Possible Cause Correction
LOW SIDE LOW -
HIGH SIDE LOW
(1) System refrigerant is low.
(2) Expansion valve is restricted.
(1) Evacuate, leak test and charge the system.
(2) Replace the expansion valve.
LOW SIDE HIGH -
HIGH SIDE LOW
(1) Internal leak in the compressor - worn. (1) Remove the compressor cylinder head and
inspect the compressor. Replace the valve
plate assembly if necessary. If the
compressor pistons, rings or cylinders are
excessively worn or scored replace the
compressor.
(2) Cylinder head gasket is leaking. (2) Install a replacement cylinder head gasket.
(3) Expansion valve is defective. (3) Replace the expansion valve.
(4) Drive belt slipping.
(4) Adjust the belt tension.
LOW SIDE HIGH -
HIGH SIDE HIGH
(1) Condenser fins obstructed.
(2) Air in the system.
(1) Clean the condenser fins.
(2) Evacuate, leak test and charge the system.
(3) Expansion valve is defective. (3) Replace the expansion valve.
(4) Loose or worn fan belts. (4) Adjust or replace the belts as necessary.
LOW SIDE LOW -
HIGH SIDE HIGH
(1) Expansion valve is defective.
(2) Restriction in the refrigerant hose.
(1) Replace the expansion valve.
(2) Check the hose for kinks - replace if
necessary.
(3) Restriction in the receiver/drier. (3) Replace the receiver/drier.
(4) Restriction in the condenser.
(4) Replace the condenser.
LOW SIDE AND HIGH
SIDE NORMAL
(INADEQUATE COOLING)
(1) Air in the system.
(2) Moisture in the system.
(1) Evacuate, leak test and charge the system.
(2) Evacuate, leak test and charge the system.
70146
L-18