TM-9-2350-311-20-1

HOWITZER, MEDIUM, SELF-PROPELLED, 155MM; M109A2, M109A3, M109A4 AND M109A5

TECHNICAL MANUAL; UNIT MAINTENANCE MANUAL FOR HULL, POWERPLANT, DRIVE CONTROLS, TRACKS, SUSPENSION, AND ASSOCIATED COMPONENTS

AUGUST 1994

TM-9-2350-311-20-1 - Page 126 of 1275

TM 9-2350-311-20-1

3-3 TROUBLESHOOTING CHART — CONTINUED

b. MASTER RELAY CIRCUIT — CONTINUED

(2) MASTER SWITCH INDICATOR LIGHT FAILS TO

OPERATE; MASTER SWITCH IS ON — CONTINUED

CONTINUED FROM STEP F

u

1. Reconnect connector to voltage

regulator.

2. Disconnect engine disconnect bracket-to-

bulkhead wiring harness from driver’s

bulkhead.

3. Place red lead of multimeter in socket B

(lead 400/459B) and black lead to ground.

4. Turn MASTER switch ON and check for

voltage.

5. Turn MASTER switch OFF.

I

Is voltage present?

Replace or repair lead 400/459B of

engine disconnect bracket-to-

bulkhead wiring harness (para 8-45,

M109A2/M109A3; para 8-48,

M109A4/M109A5).

CONTINUED ON NEXT PAGE

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