TM 9-2320-361-20 Table 2-4. Electrical Troubleshooting (Contd). MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION 25. DIRECTION SIGNAL INOPERATIVE Test 1. Test turn signal lamps. Step 1. Turn main light switch to SERVICE DRIVE. Step 2. Place turn signal in left or right position, turn signal should flash on both sides. a. If turn signal on left or right operates, go to test 2. b. If turn signal on left or right operates, but does not flash, go to test 3. 2-110