RING-RETAINING 8C8840 - Caterpillar

Right Rear Leg Rotation Enable and Rotation Switches
Refer to Illustrations 3 and 11 for switch locationsPossible Cause of a Rear RH Column Drive Control Fault.
Voltage Checks Leg Rotation Enable Switch
When stop switch (5) is pressed, there should be 27 v at wire 139-OR on Terminal 3 of the leg rotation enable switch. Refer to Illustration 1.
When rotation enable switch is toggled on, 27 v goes through switch to wire 175-PK on Terminal 2 to the Machine ECM Pin 19.Voltage Checks Leg Rotation Switch
The leg rotation switch is a three position switch that is spring centered. Supply voltage to the leg rotation switch is from Pin 23 of Machine ECM to Terminal 2 wire 924-WH of switch.
When the leg rotation switch is spring centered, there should be 2.15 v at T2, .780 v at T1, and 4.5 v at T3.
When the leg rotation switch is toggled In to retract, there should be 1.1 v at T2. There should be 1.1 v at T1, And there should be 4.3 v at T3.
When the leg rotation switch is toggled Out to extend, there should be 4.0 v at T2. There should be 1.4 v at T1. And there should be 4.0 v at T3.Resistance Checks Leg Rotation SwitchNote: There is a 6-pin Deutsche receptacle resistor assembly on the leg rotation
When resistance is measured from Pin 1 to Pin 2, the resistance should be 2.171 ohm
When resistance is measured from Pin 1 to Pin 3, the resistance should be 2.634 ohm
When resistance is measured from Pin 1 to Pin 5, the resistance should be 2.303 ohm
When resistance is measured from Pin 1 to Pin 6, the resistance should be 1.486 ohm
When resistance is measured from Pin 2 to Pin 3, the resistance should be 0.464 ohm
When resistance is measured from Pin 2 to Pin 5, the resistance should be 4.471 ohm
When resistance is measured from Pin 2 to Pin 6, the resistance should be 3.654 ohm
When resistance is measured from Pin 3 to Pin 5, the resistance should be 4.931 ohm
When resistance is measured from Pin 3 to Pin 6, the resistance should be 4.121 ohm
When resistance is measured from Pin 5 to Pin 6, the resistance should be 0.817 ohm
Pin 4 is blankRight Rear Leg Horizontal Locking Cylinder Proximity Sensor
Refer to Illustration 12 for horizontal locking cylinder and proximity sensor locationsPossible cause of Fault locking RH rear column fault.
Voltage Checks
When the rod of the horizontal lock cylinder is extended, there should be 27 v at T970-GY power (Pin C) and 27 v at T981-OR signal Pin A.
When the rod of the horizontal lock cylinder is retracted, there should be 27 v at T970-GY power (Pin C) and 0 v at T981-OR signal Pin A.
If the cylinder is extended and the proximity sensor reads 0 v Signal, a fault locking RH rear column will occur when hydraulics are activated.
The sensor could be shorted to ground. There could be excessive grease in front of the sensor so the sensor cannot detect metal. Or