PIN 7Y7828 - Caterpillar

Make sure that the key start switch is in the OFF position. Disconnect the C1 connector. Disconnect the C2 connector. Proceed to the "Check for Continuity Between the C1 (P1) Connector and the Chassis Ground on the Machine" section of this document.Check for Continuity Between the C1 (P1) Connector and the Chassis Ground on the Machine
The expected result of the check is no electrical continuity between the terminals C1 (P1) on the machine controller and the chassis ground terminals on the machine.If there is no electrical continuity between the terminals C1 (P1) on the machine controller and the chassis ground on the machine, proceed to the "Measure the Electrical Voltage Between the C2 (P2)Terminals of the Governor Actuator or the Engine Controller and the Chassis Ground on the Machine" section of this document.If there is electrical continuity, there is a problem with a short to ground in harness (W1) and harness (W2). Replace the harness (H1) and the harness (H2) in order to repair the problem.Measure the Electrical Voltage Between the C2 (P2)Terminals of the Governor Actuator or the Engine Controller and the Chassis Ground on the Machine
Connect the C1 connector. Turn the key start switch to the ON position. Do not start the machine. The electrical voltage should be between 0.5 volts and 7 volts.If the electrical voltage is between 0.5 volts and 7 volts, the problem could be in the engine controller. Use the troubleshooting procedures in the Engine Service Manual in order to troubleshoot the engine.If the electrical voltage is not between 0.5 volts and 7 volts, the problem is in the machine controller. Replace the machine controller in order to solve the problem.Check the Warning Message on the Monitor
The warning message for overheating or for low engine oil pressure should not be displayed on the monitor.If the warning for overheating or the warning for low engine oil pressure are not displayed on the monitor, proceed to the "Check the Position of the Rotary Switch and the Engine Speed Dial Indicator on the Monitor" section of this document.If the warning for overheating or the warning for low engine oil pressure are displayed on the monitor, clear the warning message from the monitor.Check the Position of the Rotary Switch and the Engine Speed Dial Indicator on the Monitor
The position of the rotary switch should coincide with the engine speed dial indicator on the monitor at every position.If the position of the rotary switch coincides with the engine speed dial indicator on the monitor at every position, use the troubleshooting procedures in the Engine Service Manual in order to troubleshoot the engine.If the position of the rotary switch does not coincide with the engine speed dial indicator on the monitor at every position, proceed to the "Check the Electrical Connector" section of this document.Check the Electrical Connector
Illustration 3 g01062196
Location Of The Rotary Switch Assembly In The Right Hand Console (1) 106-0107