SFWR GP-A3000 5286057 - Caterpillar

Water Spray Electrical Schematic
Illustration 1 g02024487
Power DistributionWhen the main power relay is energized, power is available at the ECM fuse and the water spray fuse through 112-PU wires. When the ECM fuse is closed, power is available at contact "1" of the propulsion sensor and terminals "2", "47", "48", "49", "50" of the ECM through 135-BU wires. When the water spray fuse is closed, power is available at contact "3" of the number one water spray relay through the 110-GN wire.After the ECM receives power, it begins to monitor the circuit at terminal "22". The water spray master switch on the propulsion lever provides the input signal to this terminal. When the water spray master switch is depressed, the circuit at terminal "22" of the ECM is complete. This prompts the ECM to initiate the water spray control logic.Since the water spray master switch is a momentary type switch, the circuit at terminal "22" of the ECM is only complete while the switch is held. When the switch is released, the circuit at terminal "22" returns to its natural state. The ECM monitors the number of times that the water spray master switch is closed to determine if the water spray system is ON or OFF. The first time the water spray master switch is closed (and on all subsequent odd numbered times), the ECM enables the water spray system. The second time the switch is depressed (and on all subsequent even numbered times), the ECM disables the water spray system.When the ECM determines that the water spray system is ON, an output signal is generated from terminal "45". This signal is sent through the C935-PU wire to contact "2" of the water spray timer and to the water spray indicator. During machine operation, the ECM monitors the signal at terminal "24" from the propulsion sensor to determine the position of the propulsion lever. Based on this input, the ECM determines whether an output signal should be generated from terminal "35" or terminal "46". These signals are used in the propulsion circuit and the water spray circuit.When the ECM determines that the propulsion lever is in the REVERSE range, an output signal is generated at terminal "46". This signal is sent through the C936-GY wire to the coil of the number two water spray relay. When the ECM determines that the propulsion lever is in the NEUTRAL position, an output signal is generated at terminal "35". This signal is sent through the 330-YL wire to the coil of the neutral stop relay.The number two water spray relay and the neutral stop relay work in conjunction to control the water spray system when the water pump selector switch is in the AUTOMATIC position. The number one water spray relay is used to control which water pump is active, and the neutral stop relay prevents either water spray motor from operating when the propulsion lever is in the NEUTRAL position. These relays only impact the system's operation when the system is