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 265 of 1275

TM 9-2350-311-20-1

NOTE

Perform step M only if vehicle is equipped with an

adjustable regulator. If not, replace regulator (para 8-3).

CONTINUED FROM STEP L

I

3-3n)

Troubleshoot

air cleaner blower

M

Do not check or adjust voltage regulator except

as follows:

1. Make sure batteries are fully charged while

checking and/or adjusting regulator

(TM 9-2350-311 -10).

2. Connect red lead of multimeters to positive

battery cable terminal and black lead

to negative battery cable terminal.

3. Start engine and run at approximately 1000

rpm. Run engine as required to bring engine

compartment, regulator, and batteries to

normal operating temperature.

4. During above warm-up period, increase

engine speed to approximately 2500 rpm

and then return to idle speed (750 rpm) while

observing multimeters. Voltage reading

should not vary more than ± 0.1 volt during

above check. This also provides a check on

tightness of wiring connection. Turn

headlights on and off several times.

Multimeters

needle may vary slightly, but

should return to its original voltage quickly.

5. Turn off all major vehicle electrical

components and turn on vehicle headlights.

6. Open transmission left access door and

remove square head pipe plug from end of

voltage regulator (between and above

harness connectors).

[

CONTINUED ON NEXT PAGE

3-155

motor circuit (para 3-31, 3-3m, or