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 388 of 1275

TM 9-2350-311

-20-1

3-3 TROUBLESHOOTING CHART — CONTINUED

z.

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

CONTINUED

CONTINUED FROM STEP B

I

D

1. Disconnect battery ground leads.

2. Place a jumper wire from pin A to socket A

(lead 400).

3. Place red lead of multimeters in socket C (lead

402) and black lead to ground.

4. Turn MASTER switch ON, HEAT

SELECTOR switch to LOW and check for

voltage.

5. Turn MASTER and HEAT SELECTOR

switches OFF.

Is voltage present?

E

1. Reconnect accessory control box-to-heater/

blower wiring harness to accessory control

box.

2. Disconnect lead 10 of power lead wiring

harness from accessory control box.

3. Place red lead of multimeters in lead 10 and

black lead to ground.

4. Turn MASTER switch ON and check for

voltage.

5. Turn MASTER switch OFF.

Is voltage present?

Troubleshoot master relay circuit

CONTINUED ON NEXT PAGE

3-288

(para 3-3b).