TM-9-2350-311-20-2 Maintenance Manual Volume 2 for M109 Cab Download
Page 249 of 828
TM 9–2350–311–20–2 3–137 j. NBC SYSTEM CIRCUIT — CONTINUED (7) NBC CONTROL BOX ASSEMBLY INDICATOR LIGHT ILLUMINATES, BUT ASSISTANT GUN- NER’S M3 ELECTRICAL HEATER DOES NOT OPERATE. INITIAL SETUP Applicable Configuration M109A4/M109A5 howitzers Test Equipment Multimeter (item 6, Appx H) Tools Artillery and turret mechanic’s tool kit (SC 5180–95–CL–A12) Equipment Condition Vehicle MASTER switch to OFF (TM 9–2350–311–10) CAB NBC POWER switch to OFF (TM 9–2350–311–10) 1. Disconnect wire 136C from assistant gunner’s M3 electrical heater. 2. Turn MASTER and CAB NBC POWER switches to ON. 3. Place red multimeter lead in wire 136C and black multimeter lead to ground. 4. Check for voltage. Is battery voltage present? yes no A Replace M3 electrical air heater (para 17–2). B CONTINUED ON NEXT PAGE – + ASSISTANT GUNNER’S HEATER WIRE 136C – + 1. Turn MASTER and CAB NBC POWER switches to OFF. 2. Disconnect NBC power lead assembly at J2 connector on NBC control box assembly. 3. Place one multimeter lead in wire 136C and other lead to pin C of NBC power lead assembly connector. 4. Check for continuity. Is continuity present? WIRE 136C NBC POWER LEAD ASSEMBLY CONNECTOR PIN C