TM 9-2320-363-34-1
PROBLEM - LITTLE OR NO AIRFLOW
Possible Cause
The blower is not operating
There are restrictions or leaks in the
Examine ail air ducts and remove any blockages. Stop any leaks or
air ducts.
replace any 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.
Remedy
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.
PROBLEM - WARM AIRFLOW WHEN AIR CONDITIONER IS ON
Possible Cause
There is no refrigerant charge in the
system.
Moisture in the system.
The refrigerant compressor is not
operating.
Remedy
Repair any leaks, evacuate the system, replace receiver-drier, and add a
full charge of refrigerant.
If moisture is in the system, ice crystals may form at the expansion valve,
blocking the flow of refrigerant (off and on). Recover the refrigerant
charge, replace the receiver-drier, evacuate the system, and add a full
charge of refrigerant.
If the refrigerant charge is low, charge the system. Repair any leaks.
The refrigerant compressor clutch needs repair or replacement.
PROBLEM - LOW EVAPORATOR COIL OUTLET PRESSURE (LOW COMPRESSOR SUCTION
PRESSURE)
Possible Cause
Remedy
The expansion valve is not working.
Replace the expansion valve.
Remove the line restrictions.
There are restrictions in the line to
the expansion valve.
There is an insufficient refrigerant
charge in the system.
Locate the leak. Recover the charge, replace the receiver-drier, and add
a full refrigerant charge.
Change 1
2-28.7
