HEATER FAN MOTOR WILL NOT OPERATE

TM 9-2320-279-20-1

Troubleshooting Malfunctions (Cont)

Table 2-9 Troubleshooting (Cont)

Malfunction

Test or Inspection

Corrective Action

Remove heater compartment cover, and check heater fan switch and wiring for continuity.

Step 1.

Replace defective heater fan switch (para 7-42) or repair wiring.

Check heater resistor coils for continuity.

Step 2.

Replace defective resistor (para 18-19).

Check heater wiring circuit for continuity. Refer to FO-1, Electric Diagram.

Step 3.

If heater wiring circuit is defective, repair defective wires or connectors.

Use multimeter to check voltage going into heater is 22-28 volts.

Step 4

If voltage is 22-28 volts, replace motor (para 18-20).

Remove heater compartment cover. Check circuit breaker No. 11 for continuity (fig. 2-2).

Step 5.

Replace defective circuit breaker No. 11 (para 7-43).

Check for 24 vdc at input terminal at circuit breaker No. 5.

Step 6.

If 24 vdc is not present, trace wiring and find problem. Refer to FO-1 Electric Dia-

gram.

Change 3