TM-9-2320-361-24-1 Field Maintenance Manual Volume 1 for M44A2 Series Trucks
Page 206 of 1176
MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION 1. NO ALTERNATOR OUTPUT 5. Measure voltage at terminal end of lead 568. Test 4. Test positive output of alternator. NOTE • Access cover was removed in test 3. • Input amps decrease in input voltage normally causes an increase in alternator output voltage. 1. Start engine (TM 9-2320-361-10). 2. Set engine speed at 1200 RPM. 3. Turn headlights and accessories to ON position. 4. Use multimeter to measure alternator output voltage at positive terminal (lead 2). Test 5. Test voltage drop on lead 2. Place multimeter positive lead on alternator positive output. Place multimeter negative lead on starter solenoid lug 2. Test 6. Test battery voltage into power accessory switch (WP 0012 00, table 3, malfunction 1, test 4). 1. Disconnect lead 1 from pin D of power accessory switch. 2. Turn power accessory switch to ON position. 1. If battery voltage is present (normal), the alternator is defective. Go to test 4 and check positive output of alternator. 2. If voltage is not present, an open lead or bad connection exists in lead 568. Repair or replace lead (WP 0090 00). Return to test 2. 1. If output voltage is between 24.0 and 26.0 VDC, replace alternator (WP 0085 00). 2. If output voltage is more than 28.5 VDC, go to test 5 and check voltage drop on lead 2. 1. If voltage drop on lead 2 is greater than 0.4 volts, repair or replace lead (WP 0090 00). Go to test 2. 2. If voltage drop on lead 2 is less than 0.4 volts (normal), voltage regulator output is too high. Replace alternator (WP 0085 00). TM 9-2320-361-24-1 0012 00 0012 00-22 BATTERY AND CHARGING SYSTEM TROUBLESHOOTING (Contd) Table 3. Charging System (60 Amp) Troubleshooting Procedure (Contd).