Table 4-2. Unit Troubleshooting-continued -706880226

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

Table 4-2.

Unit Troubleshooting-Continued

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

ELECTRICAL SYSTEM-CAB CONTROLS AND INDICATORS-Continued

ENGINE HOUR METER DOES NOT OPERATE

(Refer to Electrical Wiring Diagrams, Appendix H, Sheet 2 of 16.)

Step 1. Check gauge.

Replace gauge (see para 4-93).

Step 2. Check engine hour PSI switch for proper operation.

Replace PSI switch (see para 4-9.4).

Step 3. Check for +12V at ignition accessory buss for +12V.

Refer to "+12 volts not present at ignition accessory buss" troubleshooting procedure.

Step 4. Check for +12V at circuit breaker #1 on ignition accessory buss.

Replace breaker (see para 4-99).

Step 5. Check wiring for continuity.

Replace wire (see para 4-9.4).

AERIAL HOUR METER DOES NOT OPERATE WITH AERIAL MASTER ON,

PARK BRAKE ON, AND SHIFT SELECTOR IN NEUTRAL

(Refer to Electrical Wiring Diagrams, Appendix H, Sheet 2 of 16.)

Step 1. Check gauge.

Replace gauge (see para 4-93).

Step 2. Check PTO fuse.

Replace fuse (see para 4-9.4).

Step 3. Check aerial solenoid for proper operation.

Replace solenoid (see para 4-9.4).

Step 4. Check neutral safety relay (CRY032 in DDEC hi-idle interlock module) for +12V at wi e 11 17.

Refer to "neutral safety circuit does not provide +12V signal to CRY030" troubleshooting

procedure.

4-97