PCB ENGINE CONNECTOR Disconnect negative battery cable before disconnecting and reconnecting protective control box/distribution box harness. TM 9-2320-280-20-1 REFERENCE INFORMATION Change 1           2-335 6 3 A B E ENGINE CONNECTOR BODY CONNECTOR WAIT-TO-START LAMP 27 27F 27P 27D 27L 27K 571 571A 459B 569A/583 569C 583B 54A 458A PROTECTIVE CONTROL BOX/DISTRIBUTION BOX GLOWPLUG CONTROLLER INSTRUMENTS CIRCUIT Engine temperature must be below 120°F (49°C) in order to make this test, otherwise normal operation of the glowplug controller will cause the circuit to be open. Replace harness and glowplug controller, refer to (para. 4-29).    GLOWPLUG   CONTROLLER HARNESS A B C D E F G H I 1 3 4 5 6 2 CONTINUITY (RESISTANCE) MULTIMETER 1. Set the voltmeter to an ohms scale of about 1000 ohms. 2. Connect the RED and BLACK leads to the connections stated in the question. 3. Be sure to read the correct scale.  Less than 5 ohms indicates continuity.  For an open circuit, the meter should peg full scale (needle all the way to the left). 0-4500 OHMS STE/ICE-R TEST 91 1. Connect RED clip and BLACK clip to the terminations indicated in the question.  RED to the first, BLACK to the second. 2. Start Test 91, 0-4500 ohms. 3. Displayed reading is in ohms.  Less than 5 ohms is continuity.  If the resistance is over 4500 ohms, STE/ICE displays “9.9.9.9.” 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. WARNING