55072 Mercruiser THURST WASHER, BEARING CARRIER

Illustration 1 g01165526
Schematic for the air shutoff system
Table 1
Troubleshooting Test Steps Values Results
1. Inspect the Electrical Connectors and the Wiring
A. Remove electrical power from the ECM.
B. Verify that the air shutoff mechanisms are set to the OPEN position.
C. Thoroughly inspect the connectors. Also, inspect the connections at the air shutoff solenoid. Refer to Troubleshooting, "Electrical Connectors - Inspect" for more information.
D. Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit for the air shutoff system. Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit for the air shutoff system.
E. Check the allen head screw on each ECM connector for the proper torque. Also, check the allen head screw on the customer connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
F. Check the harness and the wiring for abrasion and for pinch points from the air shutoff solenoid to the ECM.
Electrical Connectors and Wiring
Result: The electrical connectors and wiring are OK.
Proceed to Test Step 2.
Result: The electrical connectors are NOT OK.
Repair: Repair or replace the damaged parts and return to service.
Illustration 2 g01165714
Location of the test lamp
Table 2
Troubleshooting Test Steps Values Results:
2. Test the Operation of the Control Solenoid for the Air Shutoff Relay
A. Turn the keyswitch to the OFF position.
B. Remove the wire from the output of the air shutoff relay.
C. Connect a test lamp between the output of the solenoid for the air shutoff relay and engine ground.
D. Start the engine.
E. Activate the overspeed verify switch.
F. Monitor the test lamp while you increase the engine speed past 75 percent of the programmed overspeed setpoint.
G. Stop the engine.
H. Remove the test lamp from the circuit. Restore the wiring to