TM9-4120-400-14
TROUBLESHOOTING
MALFUNCTION
TEST OR INSPECTION
C O R R E C T I V E ACTION
AIR CONDITIONER DOES NOT START IN ANY MODE.
Step 1. Check if circuit breakers are tripped.
Reset circuit breakers.
Step 2. Check if input power has been disconnected.
Connect input power.
If input power has been disconnected for an unknown period of time, do not start
in COOL MODE until power has been reconnected for a minimum of four hours.
Step 3. Check for loose or damaged electrical connectors or damaged wires in wiring harnesses.
Tighten or replace connectors, or repair damaged wires.
Step 4. Check that internal wiring is connected to terminal board TB3 for correct input connector.
Step5. Check for defective circuit breaker. (See para 4-25 or 4-33.)
Replace circuit breaker if defective.
Step 6. Check for defective MODE SELECTOR switch. (See para 4-24.)
Replace switch if defective.
CONDITIONED (EVAPORATOR) AIR FAN DOES NOT START OR STOPS DURING
OPERATION IN ANY MODE.
Step 1. Check operation of evaporator fan motor. (See para 4-41.)
Test motor. Replace motor if defective.
Step 2. Check operation of MODE SELECTOR switch. (See para 4-24.)
Test switch. Replace switch if defective.
Tighten or replace connectors, or repair or replace damaged wires.
Relieve binding or replace fan.
4-31