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 374 of 1275

TM 9-2350-311-20-1

3-3 TROUBLESHOOTING CHART — CONTINUED

x.

INSTRUMENT PANEL/PORTABLE INSTRUMENT

(1) ONE OR MORE INSTRUMENT PANEL LIGHTS FAIL

PANEL LIGHT CIRCUIT — CONTINUED

TO OPERATE — CONTINUED

CONTINUED FROM STEP A

1. Install inoperative panel light bulb (para

3.

4.

5.

6.

7.

8.

8-17).

Disconnect battery ground leads.

Disconnect portable instrument panel wiring

harness from portable instrument panel

disconnect.

Place a jumper wire from socket C to pin C

(lead 459) and from socket P to pin P (lead

459B).

Place red lead of multimeters on pin J (lead 40)

and black lead to ground.

Reconnect battery ground leads.

Turn MASTER and instrument panel light

switches ON and check for voltage.

Turn MASTER and instrument panel light

switches OFF.

Is voltage present?

portable instrument panel wiring

3-274

CONTINUED ON NEXT PAGE

harness (para 8-57).