TM-9-2350-311-20-2 Maintenance Manual Volume 2 for M109 Cab Download
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TM 9–2350–311–20–2 3–133 j. NBC SYSTEM CIRCUIT — CONTINUED (5) NBC CONTROL BOX ASSEMBLY INDICATOR LIGHT ILLUMINATES, BUT CANNONEER NO. 1’S M3 ELECTRICAL AIR 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. 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 136B and other lead to pin A of NBC power lead assembly connector. 4. Check for continuity. Is continuity present? NBC POWER LEAD ASSEMBLY CONNECTOR PIN A 1. Disconnect lead 136B from cannoneer no. 1’s M3 electrical air heater. 2. Turn MASTER and CAB NBC POWER switches to ON. 3. Place red multimeter lead in wire 136B and black lead to ground. 4. Check for voltage. Is battery voltage present? A yes no Replace M3 electrical air heater (para 17–2). B CONTINUED ON NEXT PAGE WIRE 136B WIRE 136B – + GUNNER’S HEATER – + 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 136B and other lead to pin A of NBC power lead assembly connector. 4. Check for continuity.