TM-9-2350-311-20-1 Maintenance Manual for Volume 1 M109 Hull Download
Page 277 of 1275
TM 9-2350-311-20-1 CONTINUED FROM STEP J 2. 3. 4. 5. 6. 7. 8. 9. 10. 1. Reconnect rectifier-to-voltage regulator wiring harness to rectifier, Disconnect battery ground leads. Disconnect rectifier-to-voltage regulator wiring harness from voltage regulator. Place jumper wires from pin E (lead 3) to a battery negative terminal and pin B (lead 1 ) to the positive terminal of same battery. Disconnect lead 2A from battery positive terminal. Reconnect battery ground leads. Turn MASTER switch ON and run vehicle engine at idle speed (750 rpm). Set multimeter on dc scale and place red lead of multimeter on lead 2A and black lead to ground. Check for voltage. Turn MASTER switch and engine OFF. Is voltage above 27.5 Vdc? Repair or replace rectifier-to-voltage regulator wrong harness (para 8-60). NOTE Batteries can be totally discharged within 4 to 6 hours if air cleaner blower motor system is malfunctioning or if blower motors operate full time. Troubleshooting step L provides a basic test of blower motor circuit by testing blower motor relay output voltage to voltage regulator (lead 27 B). If blower motor relay output is 24 Vdc or greater (battery power) with voltage regulator disconnected from circuit, voltage regulator is malfunctioning/inoperative and will not charge battery. If voltage is less than 24 Vdc (battery power), blower motor circuit is malfunctioning and discharging battery. CONTINUED ON NEXT PAGE 3-177