PLATE AS 3992371 - Caterpillar

Illustration 1 g00627903
Schematic of the blade control handleThe following procedure is for the manual select switch. This switch has two inputs to the ECM: "N/O" (wire J945-WH) and "N/C" (wire J946-OR). During normal operation, one of the switch input is open and the other input is grounded. If both inputs are in the same state, the ECM will detect a diagnostic code. This diagnostic code is detected when both switch inputs are open or shorted to the + battery.The possible causes of this diagnostic code are listed:
Both inputs are open.
A short to battery
A failed switch
The ECM may have failed. This is unlikely.Note: Ensure that CID 0875 FMI 03 is active. The following procedures may create other diagnostic codes that are detected by the ECM. Ignore these created diagnostic codes and clear the diagnostic code when this diagnostic code has been corrected. Test Step 1. CHECK FOR AN OPEN CIRCUIT.
Turn the disconnect switch and the key start switch to the OFF position.
Disconnect the J1 machine harness connector from the ECM.
At the J1 machine harness connector, measure the resistance from contact J1-45 (wire J945-WH) to contact J1-9 (wire J764-BR) with the switch in the N.O. position. The switch is pressed.
At the J1 machine harness connector, measure the resistance from contact J1-44 (wire J946-OR) to contact J1-9 (wire J764-BR) with the switch in the N.C. position. The switch is not pressed.Expected Result:The resistance should be less than 5 ohms for each measurement.Results:
YES - The resistance is less than 5 ohms for each measurement. Proceed to test step 3.
NO - The resistance measurement is NOT less than 5 ohms for one or both measurements. The harness or the switch has failed. Proceed to test step 2.Test Step 2. CHECK THE RESISTANCE OF THE SWITCH.
Disconnect the machine harness from the blade control handle.
Place the switch in the N.O. position. Measure the resistance of the switch from contact N to contact R of the connector for the blade control handle. The switch is pressed.
Place the switch in the N.C. position. Measure the resistance of the switch from contact P to contact R of the connector for the blade control handle. The switch is NOT pressed.Expected Result:The resistance measurement should be less than 5 ohms for each measurement.Results:
OK - The resistance measurements are less than 5 ohms. The switch is correct.Repair: The machine harness has failed. Repair the machine harness or replace the machine harness.STOP
NOT OK - The resistance is not less than 5 ohms for one or both measurements.Repair: The switch has failed. Replace the blade control handle. Perform the calibration for the blade control handle. See Testing and Adjusting, "Calibration". Verify that the new blade control handle corrects the problem.STOPTest Step 3. CHECK FOR A SHORT.
At the J1 machine harness connector, measure the resistance from contact J1-44 and contact J1-45 to all other J1 and J2 contacts.Expected Result:The resistance measurement should be greater than 5000 ohms for each measurement.Results:
OK - The resistance measurement is greater than 5000 ohms for each measurement.Repair: It is unlikely