TM-9-2320-361-24-1 Field Maintenance Manual Volume 1 for M44A2 Series Trucks

TM 9-2320-361-24-1 0013 00 0013 00-4 LIGHTING AND WIPER SYSTEM TROUBLESHOOTING (Contd) MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION 1. HEADLIGHT DOES NOT OPERATE ON LOW OR HIGH BEAM, OR BOTH HEADLIGHTS INOPERATIVE (Contd) Test 3. Test lighting system harness connector to voltage. 1. Turn main light switch lever to OFF position. 2. Remove light switch assembly from instrument panel (WP 0101 00). 3. Disconnect harness connector from light assembly (WP 0101 00). CAUTION Voltage at pin F is tied directly to battery without fuse protection. Insert jumper wire in pin of faulty circuit being tested first to prevent energized jumper wire from touching ground and damaging wire harness. 4. Check for battery voltage at harness connector at pin F. 5. Check circuit 15 for loose connections or broken wire. 6. Reconnect front wiring harness connector to light switch and reinstall light switch (WP 0101 00). 1. If battery voltage is indicated at pin F, connect a jumper wire from pin F to socket pin of faulty circuit. 2. If lamps light with jumper wire connected, replace main light switch (WP 0101 00). 3. If battery voltage is not indicated, go to step 5. Repair broken wire. MAL 1 TEST 3 STEP 4 MAIN LIGHT SWITCH HARNESS CONNECTOR SOCKET WIRE NO. CIRCUIT A B C D E F H J K L M N 75 40 22 19 20–24 15 21 460–461 75 491 16 23 STOPLIGHT SWITCH PANEL LIGHTS DIRECTIONAL CONTROL BLACKOUT (B.O.) DRIVING LIGHT B.O. MARKER LIGHTS BATTERY POSITIVE CABLE 24 VOLTS SERVICE REAR LIGHTS DIRECTIONAL INDICATOR STOPLIGHT SWITCH SERVICE PARKING LIGHTS SERVICE HEADLIGHTS B.O. STOPLIGHT Table 1. Lighting System Troubleshooting Procedures (Contd). N H J F E M D C L B A K Legend