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 399 of 1275

TM 9-2350-311-20-1

CONTINUED FROM STEP E

F

1. With multimeters disconnected and socket B

(lead 159A) grounded, place VENTILATOR

BLOWER switch in opposite position of

where voltage was obtained in steps D and E.

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

159B) and black lead in socket A (lead 159C).

3. Turn MASTER switch ON and check for

voltage.

4. Turn MASTER switch OFF.

Is voltage present?

Repair or replace leads 159A, 159B and/

or 159C accessory control box ventilator

blower switch lead (para 8-67).

CONTINUED FROM STEP E

G

1. Reconnect accessory control box-to-heater/

blower wiring harness to accessory control

box.

2. Disconnect lead 10 from accessory control

box.

3. Place red lead of multimeter 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

(para 3-3b).

CONTINUED ON NEXT PAGE

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