TM-5-3805-254-20-1

TRUCK, DUMP, 20 TON, 6X4, ON-OFF HIGHWAY 71,000 GVW, IHC MODEL F-5070 (CCE)

TECHNICAL MANUAL; ORGANIZATIONAL MAINTENANCE MANUAL VOLUME 1 OF 2

JANUARY 1988

TM-5-3805-254-20-1 - Page 178 of 790

TM 5-3805-254-20.1

ORGANIZATIONAL TROUBLESHOOTING - CONTINUED

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

6.

ENGINE TACHOMETER DOES NOT WORK.

Step 1.

Using 1-inch open-end wrench, unscrew and take tachometer cable (1) off cable adapter (2) on fuel pump

(3).

Have assistant start engine (TM 5-3805-254-10).

Look into cable adapter (2) and see if cable drive (4)

is turning.

Have assistant shut down engine (TM 5-3805-254-10).

a.

If cable drive (4) is not turning, notify Direct Support Maintenance.

b.

If cable drive (4) is turning, screw tachometer cable (1) onto cable adapter (2) and tighten using 1-

inch open-end wrench.

Go to step 2.

Step 2.

Open lower center instrument panel (page 2-424).

Using 3/4-inch open-end wrench, unscrew and take

tachometer cable (1) off tachometer head (5).

Start engine (TM 5-3805-254-10) and see if cable core (6) is

turning.

Shut down engine (TM 5-3805-254-10).

a.

If cable core (6) is not turning, replace tachometer drive cable (1) (page 2-1420).

b.

If cable core (6) is turning, replace tachometer head (5) (page 2-1411).

2-109