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 118 of 1275

TM 9-2350-311-20-1

3-3 TROUBLESHOOTING CHART — CONTINUED

b. MASTER RELAY CIRCUIT — CONTINUED

(1) MASTER SWITCH INDICATOR LIGHT IS LIT

Tools

General mechanic’s tool kit (item 64, Appx H)

Multimeter (item 36, Appx H)

TA-1 probe kit (item 43, Appx H)

Engine access doors open (TM 9-2350-311-1O)

A

1. Disconnect lead 459 from master relay.

2. Place red lead of multimeter in lead

459 and black lead to ground.

3. Turn MASTER switch ON, and check for

voltage.

4. Turn MASTER switch OFF.

Is voltage present?

Go to step E.

B

1. Reconnect lead 459 to master relay.

2. Disconnect lead 81 from master relay.

3. Place red lead of multimeter in lead

81 and black lead to ground.

4. Turn MASTER switch ON, and check for

voltage.

5. Turn MASTER switch OFF.

Is voltage present?

3-18