Table 4-2. Unit Troubleshooting-continued -706880272

TM 5-4210-233-14&P-1

4-2. Unit Troubleshooting-Continued

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

ELECTRICAL SYSTEM - APU AND 110-VOLT CIRCUITS - Continued

3 AUXILIARY POWER UNIT DOES NOT SHUT OFF

(Refer to Electrical Wiring Diagrams, Appendix H, Sheet 15 of 16.)

Step 1. Check switch.

Replace switch (see para 4-22 or 4-94).

Step 2. Check common/stop wire for continuity.

Replace wire (see para 4-9.4).

Step 3. Refer to APU troubleshooting procedure.

4 AUXILIARY POWER UNIT PREHEAT CONTROL DOES NOT WORK

(Refer to Electrical Wiring Diagrams, Appendix H, Sheet 15 of 16.)

Step 1. Check switch.

Replace switch (see para 4-22 or 4-94).

Step 2. Check heater element.

Replace heater element (see para 4-9.4).

Step 3. Check wires for continuity.

Replace wire (see para 4-9.4).

5 DRIVERS/PASSENGERS FLOODLIGHT (11OV) DOES NOT ILLUMINATE WITH CAB SWITCH AND

AUXILIARY POWER UNIT RUNNING(Refer to Electrical Wiring Diagrams, Appendix H, Sheet 15 of 16.)

Step 1. Check output of APU with cab or pump panel gauge.

If gauge indicates no output, refer to "APU runs, but no power output"

troubleshooting procedure above.

Step 2. Check service panel breaker is on.

Turn on breaker.

Step 3. Check bulb.

Replace bulb. (see para 4-124).

4-143