KEY 6B1295 - Caterpillar

Illustration 3 g01953219
Lower voltage enclosure on the left-hand side of the Generator (1) Stator winding temperature sensor terminal block (2) Bearing temperature sensor terminal block (3) Excitation Filed Regulator (EFR) terminal block (4) Enclosure connector for the temperature sensor circuits
At the bearing temperature sensor terminal block, disconnect the three harness circuit wires from the terminals for the bearing 2 temperature sensor.
At the bearing 2 terminal block connections, check the resistance of the temperature sensor by measuring between the positive (+) red contact and one of the two negative (-) (white) contacts.Expected Result:The acceptable range of resistance for a good temperature sensor is 80 ohms to 200 ohms.Results:
OK - The resistance measurement between the temperature sensor contacts is in the range of 80 ohms to 200 ohms. The temperature sensor is not causing the problem. Proceed to the Test Step 2 in order to check the sensor circuits.
NOT OK - The resistance measurement between the temperature sensor contacts is not in the range of 80 ohms to 200 ohms. The resistance measurement is indicating that the temperature sensor has failed.Repair: In order to confirm that the sensor is causing the problem, the harness connections can be switched. Disconnect the three harness connections from the bearing 1 temperature sensor and connect the connections to the bearing 2 temperature sensor. Connect the bearing 2 harness circuits to the bearing 1 temperature sensor.Check the status of the diagnostic code. If a MID 081, CID 3015 diagnostic code has been activated for the bearing 1 temperature sensor, the bearing 2 sensor has failed. Replace the bearing 2 temperature sensor.If the MID 081, CID 3016 diagnostic code for the bearing 2 sensor is still active, there is a problem in the bearing 2 temperature sensor circuits. The sensor is most likely not causing the problem. Before proceeding to the next test step to check the circuits, reconnect the bearing 1 circuit connections back to the original terminals. Leave the bearing 2 circuit wires disconnected.To replace a failed bearing temperature sensor:
Disconnect the three bearing circuit connections from the bearing temperature sensor terminal block. Fasten a pull wire or string to the circuit leads for use in pulling the replacement harness back through the flexible conduit.
At the Generator bearing mount for the sensor that is to be replaced, push down on the bearing retaining collar and turn counterclockwise a quarter of a turn to release the collar.
Remove the temperature sensor, spring, and collar and pull the harness out of the conduit with the pull wire.
Install the new sensor, spring, and locking collar in place. Pull the harness back through the conduit into the enclosure. Reconnect the three circuits to the terminals. Ensure that the red wire and the white wire are connected to the red and white machine harness circuits. The white return wires can be connected to either of the corresponding white harness circuits.
Check the status of the diagnostic code before installing the cover on the enclosure to verify that the problem has been resolved.STOPTest Step