NUT 7M0477 - Caterpillar

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Remove the mast from the mast mount.
Lay the mast on a suitable work area.
Remove the six hex screws (5) .
Insert center bolt (6) and remove the base plate for the mast (4) .
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Attach a wrench to bolt (8) in order to manually lower the mast to lower height if the mast tube is at the upper limit.Manually raise the mast to a higher height if the mast tube is at the lower limit.
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Upper Limit Switch
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Lower Limit Switch
Measure the resistance of both limit switches.Expected Result:The resistance measurement is less than 5 Ohms.Results:
OK - The measured resistance is less than 5 Ohms. Proceed to Test Step 2.
NOT OK - The measured resistance is greater than 5 Ohms.Repair: Repair the affected limit switch or replace the affected limit switch. Refer to Special Instruction, REHS2402, "AccuGrade Electric Mast Repair Instructions" for additional information.STOPTest Step 2. CYCLE POWER TO THE SYSTEM
Move the "Power/Setup" Switch for the AccuGrade - Grade Control System to the "OFF" position.
Turn the key start switch for the machine to the "OFF" position.
Turn the key start switch for the machine to the "ON" position.
Move the "Power/Setup" Switch for the AccuGrade - Grade Control System to the "ON" position.Results:
YES - The diagnostic code becomes inactive. Return the machine to normal operation.STOP
NO - The diagnostic code is still active.Repair: Check the connectors of the circuit board of the electric mast. Ensure that the connectors are tight. Check the connectors with caution. The tabs that are used in order to secure the connectors can break off. After checking the connectors, repeat this step. If the diagnostic code is still active, contact your Technical communicator for a possible consultation with Caterpillar.STOP