TM-9-2320-280-20 HMMWV Technical Manual Unit Maintenance Volume 1 Download
Page 357 of 890
WARNING TM 9-2320-280-20-1 REFERENCE INFORMATION Change 1 2-263 STARTER CIRCUIT BAD CONNECTIONS ARE THE MOST COMMON PROBLEM ! Sometimes, just disconnecting, cleaning and reconnecting will solve a problem. BE THOROUGH! The time you save may be your own. Refer to the functional flow schematic and check the following: 1. BATTERY - make sure all connections are clean and tight, including the shunt and power stud. 2. STARTER - check the high current (heavy gauge wire 6A) wire at the starter. Don't just check for voltage; a loose connection will have voltage but can't carry much current. A cold engine should crank at least 100 RPM. A warm engine should crank at least 180 RPM. BATTERY VOLTAGE STE/ICE TEST 67 1. Start Test 67, battery voltage. 2. Displayed reading is in volts. Batteries should be 23-25.5 volts. Batteries voltage will drop when glowplugs turn on. BATTERY VOLTAGE MULTIMETER 1. Set the voltmeter to a DC volts scale of at least 40 volts. 2. Connect the RED lead to positive and the BLACK lead to negative. 3. Be sure to read the correct scale. STE/ICE-R TEST 67 RED YELLOW GREEN RED VOLTS + - VOLTS GAUGE Disconnect negative battery cable before dis- connecting and reconnecting protective control box/distribution box harness. There is battery voltage at the PCB/distribution box at all times. Failure to disconnect battery cable will result in damage to equipment or injury to personnel. 3. PROTECTIVE CONTROL BOX/ DISTRIBUTION BOX - Unscrew BOTH connectors and look for bent or broken pins, pins pushed out of their socket, or dirt and corrosion in the connections. 4. ROTARY SWITCH - Check the wires at the switch. Don't just look. Feel the connections to make sure they're snug. Many problems can be solved by seeing with your fingers, not just your eyes. 2