TM 9-2320-302-20
0017 00-7
AIR CONDITIONING SYSTEM TROUBLESHOOTING AND TESTING - CONTINUED
0017 00
AIR CONDITIONING SYSTEM TROUBLESHOOTING
Table 1. Problem - Little or No Air Flow.
Table 2. Problem - Warm Air Flow When Air Conditioner Is On.
Table 3. Problem - Compressor Operates Too Often or Continuously.
POSSIBLE CAUSE
REMEDY
Blower is not operating.
Check for open circuit breaker. Open circuit indicates a short in electrical system,
which must be located and repaired.
Check air conditioner relays for operation. Replace as necessary (WP 0071 00).
Blower motor switch is working. Replace if necessary.
Check wiring to blower motor. Tighten any loose connections.
Check blower motor for operation. Replace blower motor if sticking or otherwise
inoperative (WP 0220 00).
Check resistor block. Replace if necessary (WP 0222 00).
CAUTION
Never attempt to bypass fuse in resistor block. To do so could cause
blower motor to overheat, resulting in serious damage to heater/air con-
ditioning system.
Restrictions or leaks in the ducts.
Examine air ducts and remove blockages. Stop any leaks or replace portion if leaks
cannot be stopped.
Ice has formed on evaporator coil.
Defrost evaporator coil before resuming operation of air conditioner.
POSSIBLE CAUSE
REMEDY
No refrigerant charge in system.
Perform air conditioner leak test (WP 0225 00).
Refrigerant compressor is not operating.
Perform air conditioner leak test (WP 0225 00).
Repair or replace drive belt (WP 0054 00).
Air
conditioner
microswitch
is
not
working.
Replace microswitch.
Ice has formed on evaporator coil.
Defrost evaporator coil before resuming operation of air conditioner.
POSSIBLE CAUSE
REMEDY
Too little refrigerant in system.
Perform air conditioner leak test (WP 0225 00).
Ice has formed on evaporator coil.
Defrost evaporator coil before resuming operation of air conditioner. Check
operation of thermostatic switch and replace as necessary.
Dirt and debris are clogging condenser
fins.
Remove dirt and debris from condenser fins.
The thermostatic switch is not working.
Replace thermostatic switch.
