Table 4-2. Unit Troubleshooting-continued -706880227

TM 5-4210233-14&P-1

Table 4-2.

Unit Troubleshooting-Continued

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

ELECTRICAL SYSTEM-CAB CONTROLS AND INDICATORS-Continued

AERIAL HOUR METER DOES NOT OPERATE WITH AERIAL MASTER ON,

PARK BRAKE ON, AND SHIFT SELECTOR IN NEUTRAL-Continued

Step 5. Check PTO relay (CRY054 in DDEC hi-idle interlock module) for+12V at wire 1205.

Replace relay (see para 4-9.4).

Step 6. Check PTO switch.

Replace switch (see para 4-95).

CAB TACHOMETER DOES NOT INDICATE ENGINE RPM

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

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

Replace breaker (see para 4-99).

Step 2. Check for +12V at tachometer.

Replace wire (see para 4-9.4).

Step 3. Replace tachometer with a new unit to confirm proper operation of DDEC tachometer send.

If new tachometer functions properly, install new tachometer.

If tachometer fails to function properly, go on to step 4.

Step 4. Check wiring from DDEC tachometer send to tachometer for continuity.

Replace wire (see para 4-9.4).

Step 5. Check DDEC for fault using Diagnostic Data Reader according to manufacturer's instructions.

Replace DDEC Engine Control Module (ECM). Notify Direct Support.

4-98