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 1196 of 1275

TM9-2350-311-20-1

- Set TEST SELECT switches to 01, press and

release TEST button.

- When Con appears, set TEST SELECT switches

to 67 and release TEST button.

VTM will alternately display battery voltage and rpm.

SET ENGINE RPM.

.

1

- Adjust engine speed to 1000 to 1200 rpm.

- Turn vehicle headlights and accessories on

to load charging system.

If VTM does not display engine speed, refer to

MEASURE BATTERY VOLTAGE

.

pulse tachometer fault isolation procedure in

TM 9-4910-571-12&P.

2

Watch display and verify that battery voltage

is within 27.5 to 28.5 Vdc.

I

Is battery voltage within limits?

After completing repair, rerun GO CHAIN tests

to verify problem has been fixed and that no

other problems exist. Start at GO 2 (Figure 2,

sheet 8) if VTM is already connected.

Otherwise start at GO 1 (Figure 2, sheet 1).

I

See Chapter 3 for further

electrical troubleshooting.

I

Is battery voltage within limits?

I

Go to Figure 2,

sheet 14.

- Turn off headlights and

accessories.

- Turn vehicle engine off.

Figure 2, Sheet 13 of 20

I-19

NOTE

NOTE