TM-9-2320-279-20-1

M977 SERIES, 8x8 HEAVY EXPANDED MOBILITY TACTICAL TRUCKS (HEMTT)

TECHNICAL MANUAL; MAINTENANCE INSTRUCTIONS; ORGANIZATIONAL MAINTENANCE, VOLUME 1 OF 3

TM-9-2320-279-20-1 - Page 200 of 985

TM 9-2320-279-20-l

Troubleshooting Malfunctions (Cont)

Table 2-9 Troubleshooting (Cont)

Malfunction

Test or Inspection

Corrective Action

ENGINE BRAKE WILL NOT OPERATE.

Step 1.

Remove circuit breaker compartment cover (para 7-43). Check circuit breaker No.9 for

continuity (fig. 2-2).

Step 2.

Replace defective circuit breaker No. 9 (para 7-43).

Check for 24 volts at input terminal on circuit breaker No. 9 (para 7-43).

If 24 volts is not present, trace wiring and find problem. Refer to FO-1, Electrical

Diagram.

Step 3

Step 4.

Check for loose or broken wires and connections. Refer to FO-1, Electrical Diagram.

Tighten loose connections, repair broken wires and connections.

Check engine brake wiring for continuity.

Repair defective wires.

Step 5.

Step 6.

Remove dash side panel, check engine brake ON/OFF switch for continuity.

Replace engine brake ON/OFF switch if defective (para 7-39).

Check engine brake HIGH/LOW switch for continuity.

Replace if defective (para 7-39).

Step 7.

If problem is not solved, notify the supervisor.

Change 3

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