Check blower switch and relay. Check A/C compressor clutch coil.
2) Ensure system is properly charged with correct amount of
refrigerant. Add refrigerant or evacuate and recharge system as
necessary. Ensure receiver-drier is not clogged. Check compressor belt
for proper tension. Check for clogged expansion valve. Check
compressor operation. Repair or replace compressor as necessary.
INSUFFICIENT AIRFLOW
Check for air leakage at air duct joint. Check for frost on
evaporator. Ensure blower motor is operating properly. Check for
obstructed air intake.
INSUFFICIENT COOLING
Ensure system is properly charged with correct amount of
refrigerant and free of air and moisture. Add refrigerant or evacuate
and recharge system as necessary. Ensure receiver-drier is not
clogged. Ensure sufficient airflow through condenser exists. Check
compressor belt for proper tension. Check compressor operation. Repair
or replace compressor as necessary. Check for clogged expansion valve.
Replace expansion valve as necessary.
INTERMITTENT COOL AIR
Check for air or moisture in system. Evacuate and recharge
system as necessary. Check for expansion valve malfunction. Replace
expansion valve if necessary. Check compressor belt for proper
tension.
TESTING
A/C SWITCH
1) Disconnect A/C switch harness connector. Using appropriate
wiring diagram as a guide, jumper appropriate terminals of A/C switch
wiring harness connector. See Fig. 4.
2) Turn blower on and momentarily turn ignition on without
starting engine. Listen for compressor clutch engagement. If
compressor clutch does not engage, check fuse and other components
wired in series with compressor clutch.
Fig. 4: A/C Switch Connector ID
Courtesy of Mitsubishi Motor Sales of America.
AIR THERMO & AIR INLET SENSORS
Fig. 3: Identifying Rear Wiper Motor Terminals (Montero)
Courtesy of Mitsubishi Motor Sales of America.
Automatic Stop Check (Montero)
1) Start motor operation by connecting battery voltage to one
terminal and grounding another terminal. See
REAR WIPER MOTOR OPERATION CHECK table. See Fig. 3. Disconnect wires
during operation to stop motor in mid-sweep.
2) Jumper terminals No. 2 and 3 together. Connect battery
voltage to remaining terminal and ground wiper motor bracket. Ensure
motor parks wiper arm.
REAR WIPER RELAY
Operation Check (Montero)
Relay is located to right of heater blower assembly. Leave
intermittent relay connected to wiring harness. Operate rear wiper and
check voltage at terminal No. 1. See Fig. 4. There should be 12 volts
when rear wiper stops. Zero volts should be present when rear wiper is
operating.
Fig. 4: Identifying Rear Wiper Relay Terminals
Courtesy of Mitsubishi Motor Sales of America.
REAR WIPER SWITCH