TM-9-2320-285-24-1

TRUCK TRACTOR, YARD TYPE, 43,500 LB GVW, DED, 4X2, ARMY MODEL M878A1

TECHNICAL MANUAL; ORGANIZATIONAL, DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE MANUAL

OCTOBER 1985

TM-9-2320-285-24-1 - Page 197 of 987

TM 9-2320-285-24-1

2-19.

INSTRUMENT PANEL TROUBLESHOOTING (CONT)

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

2.

WATER TEMP WARNING LIGHT OR BELL NOT OPERATING PROPERLY (Cont)

Step 4.

Check continuity of diodes (para 2-35f) and brown/red electrical lead connecting diodes and bell.

a.

If correct continuity is not obtained, replace diodes (para 2-35f) or repair wiring (para 2-35c(2)).

b.

If correct continuity is obtained, go to step 5 below.

Step 5.

Check continuity of wiring connecting diodes and water temperature sensor.

a.

If continuity is not obtained, repair or replace wiring (para 2-32c).

b.

If continuity is obtained, troubleshoot water temperature sensor (para 2-21).

3.

OIL PRESSURE WARNING LIGHT OR BELL NOT OPERATING PROPERLY

Step 1.

Disconnect water level sensor (para 2-29).

With engine stopped, turn key switch to on position.

OIL PRESSURE warning lamp should light and bell should sound.

a.

If lamp does not light, go to step 2 below.

b.

If bell does not sound, go to step 3 below.

c.

If lamp lights, bell sounds, and WATER LEVEL or WATER TEMP warning lamps light, go to step

4 below.

Step 2.

Check for continuity of OIL PRESSURE warning light bulb.

a.

If bulb is defective, replace (para 2-26b(4)).

b.

If bulb is not defective, repair socket and wiring as required (para 2-26b(4)).

Step 3.

Disconnect warning bell electrical leads (para 2-26c(l)).

Connect 12 Vdc power source to bell.

Bell should sound.

a.

If bell does not sound, replace (para 2-26c(1)).

b.

If bell sounds, go to step 4 below.

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