PROBLEM - LITTLE OR NO AIRFLOW

TM 9-2320-303-24-1

AIR CONDITIONING SYSTEM TROUBLESHOOTING AND TESTING - CONTINUED

0018 00

PROBLEM - LITTLE OR NO AIRFLOW

POSSIBLE CAUSE

REMEDY

The blower is not operating.

Check for an open circuit breaker. An open circuit indicates a short in the

electrical system, which must be located and repaired.

Check the air conditioner relays for operation. Replace as necessary.

Make sure the blower motor switch is working. Replace if necessary.

Check the wiring to the blower motor. If any connections are loose, securely

tighten them.

Check the blower motor for operation. Replace if sticking or otherwise

inoperative.

Check the resistor block. Replace if necessary.

CAUTION: Never try to bypass the fuse in the resistor block. To do so could

cause the blower motor to overheat, resulting in serious damage to the heater/air-

conditioning system.

There are restrictions or leaks in the air Examine all air ducts and remove any blockages. Stop any leaks or replace any

ducts.

portion where the leaks cannot be stopped.

Ice has formed on the evaporator coil.

Defrost the evaporator coil before resuming operation of the air conditioner.

PROBLEM - WARM AIRFLOW WHEN AIR CONDITIONER IS ON

POSSIBLE CAUSE

REMEDY

There is no refrigerant charge in the Perform a leak test.

system.

The refrigerant

compressor

not Leak test the system.

operating.

Drive belt needs repair or replacement.

The air conditioner microswitch is not Replace the microswitch.

working.

Ice has formed on the evaporator coil.

Defrost the evaporator coil before resuming operation of the air conditioner.

PROBLEM - HIGH COMPRESSOR DISCHARGE PRESSURE

POSSIBLE CAUSE

REMEDY

Airflow through

the

condenser

is Remove the debris from the condenser.

restricted.

Air is present in the system.

Perform a leak test.

Heavy frosting on the suction line Defrost the evaporator coil before resuming operation of the air conditioner.

suggests that the evaporator coil is

flooded.

0018 00-7