878613A 2 Mercury GEAR ASSEMBLY, Forward 1.87:1 - 15/28

Illustration 1 g03364411
Typical schematicThere are also configuration parameters that are used to configure the ECM for the type and the location of the starting motors. The following types of starting motors can be used on this engine:
Air starting motor
Electric starting motorThe wiring for each of these types of engine starting circuits is similar. Follow this procedure in order to troubleshoot the circuit diagnostics for any of these types of engine starting system.The ECM can control a secondary starting system that is installed on the engine opposite the primary starting system. Refer to Troubleshooting, "Configuration Parameters" for information that is related to the configuration parameters that are for the secondary starting system.ECM Activation of the Starting MotorsThe ECM utilizes two output drivers in order to crank the engine. Each output driver is provided with 24 VDC during engine cranking. The circuits for the output drivers utilize a return line to the ECM. This circuit includes crank relays that can be powered by an external power supply in order to override the ECM activation of the starting motors.Manual Overrides for the Engine Starting SystemThe engine can be manually cranked by using a manual crank switch that can be wired into the engine interface connector. The engine starting circuit incorporates four crank relays. When the relay coils are powered by 24 VDC, the starting motor magnetic switches are fused at the low current power distribution panel. The switch and the wiring for the circuit must be supplied by the customer.Caterpillar Electronic Technician (ET) can be used in order to override the output command that is provided by the engine state control. This override can be used to diagnose the circuit that is for the starting motor magnetic switches. View the "Starting System Relay Status" that is available in Cat ET in order to determine the status of the ECM outputs.
Illustration 2 g03323854
Table 1
Troubleshooting Test Steps    Values    Results    
1. Inspect the Electrical Connectors and the Wiring
A. Turn the main disconnect switch to the OFF position.
B. Thoroughly inspect the connectors that are associated with the starting system. Ensure that a circuit breaker has not tripped. Refer to Troubleshooting, "Electrical Connectors - Inspect " for details.
C. Perform a
45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.
D. Check the allen head screw on each ECM connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect " for the correct torque values.
E. Check the harness and the wiring for abrasion and for pinch points.
   
Connectors    
Results: The connectors and wiring are OK.
Proceed to Test Step 2
Results: The connectors and/or wiring need repair.
Repair: Repair the connectors or wiring and/or replace the connectors or wiring.
Verify that the repair eliminates the problem.
   
2. Check for Active Diagnostic Codes
A. Connect Cat ET to the service tool connector.
B. Restore the electrical power to the ECM.
C Activate the ether override.
F. Monitor the active diagnostic code screen on Cat ET. Check and record any active diagnostic codes for the starting system.
Note: Wait at least 30 seconds in