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 386 of 1275

TM 9-2350-311-20-1

3-3 TROUBLESHOOTING CHART — CONTINUED

z. PERSONNEL HEATER CIRCUIT — CONTINUED (1) PERSONNEL HEATER FAILS TO OPERATE

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

Multimeters (item 36, Appx H)

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

Personnel Required

.

Two

h

NOTE

Although personnel heater circuit differs slightly

between M109A2, M109A3, M109A4, and M109A5

Howitzers, the following troubleshooting procedure

applies to all vehicles.

1. Disconnect battery ground leads.

2 Disconnect accessory control box-to-heater/

.

blower wiring harness from personnel

heater.

3. Place red lead of multimeters in socket C

(lead 402) and black lead to ground.

4. Reconnect battery ground leads.

5. Turn MASTER switch ON, HEAT

SELECTOR switch to LOW and check for

voltage.

6. Turn MASTER and HEAT SELECTOR

switches OFF.

Is voltage present?

Notify support maintenance.

CONTINUED ON NEXT PAGE

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