TROUBLESHOOTING (Continued)

TM- 9-4910-663-34 Table 2-5. TROUBLESHOOTING (Continued) MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION 5. POLARITY REVERSING CIRCUIT a. POLARITY REVERSING CIRCUIT INOPERATIVE OR OPERATES ERRATICALLY WHEN PERFORMING GENERATOR TESTS. Step 1. Check to make sure that circuit breaker switch CB1, CIRCUIT BREAKERS CB2 DRIVE CONTROL circuit breaker, and CIRCUIT BREAKERS CB5 RELAY CONTROL circuit breaker are all set to ON position. Set POLARITY REVERSING switch S7 to POS GND position. Using ohmmeter, check for continuity between GENERATOR G± binding post and ground terminal post. If open indication is obtained, proceed to step 2; if continuity indication is obtained, proceed directly to step 4. Step 2. Set circuit breaker switch CB1 to OFF position. Disconnect lead from one terminal of coil of relay K4, and check coil of relay K4 for resistance between 56.7 and 66.2 ohms, using ohmmeter. If coil resistance is not as specified, replace relay K4. Step 3. Reconnect lead disconnected in step 2. With circuit breaker switch CB1 set to OFF position, check for continuity across appropriate terminals (fig 2-4) of POLARITY REVERSING switch S7 with switch set to POS GND position, using ohmmeter. Replace switch S7 if open indication is obtained. Step 4. With circuit breaker switch CB1 set to ON position, set POLARITY REVERSING switch S7 to NEG GND position and check for continuity between GENERATOR G- binding post and ground terminal post with ohmmeter. If continuity indication is not obtained, proceed to step 5. Step 5. Set circuit breaker switch CB1 to OFF position. Disconnect lead from one terminal of coil of relay K5, and check coil of relay K5 for resistance between 56.7 and 66.2 ohms, using ohmmeter. 2-25