ALTERNATOR GP-CHARGING 4204760 - Caterpillar

Illustration 1 g00291056
Electronic Overspeed Switch
The overspeed shutoff switch is located in the junction box. The overspeed shutoff switch must be reset before you can restart the engine. To reset the switch, push the "RESET" button. The button will remain in this position unless an overspeed condition occurs.
Always determine the cause of an overspeed before re-starting the engine.
Failure of the Speed Sensor
A failure of the speed sensor happens under any of the following conditions:
The output from the speed sensor is open.
The output from the speed sensor is shorted to ground or to supply.
The output from the speed sensor has missing pulses or extra pulses.An intermittent failure causes erratic engine control. The Engine Control Module will detect a failure of the main speed sensor. Then, the module will warn the operator through the diagnostic lamp. An automatic electronic default will use the backup speed sensor until the main speed sensor is replaced. The engine will shut off if both speed sensors fail. Failure of the Shutoff Solenoid
A failure of the shutoff solenoid happens under either of the following conditions:
The output from the speed sensor is open.
The output from the speed sensor is shorted to ground or to supply.The Engine Control Module will detect an open condition or short condition of the shutoff solenoid. If the solenoid is failed in the OPEN position, the engine will shut off. The failure of the shutoff solenoid will cause the engine to stop. The solenoid can be repositioned. This action restarts the engine.