RM-250C Reclaimer Mixer Machine Systems Caterpillar

If the shift unit will not function, the problem may be in any of the electrical components that make up the shift unit. Check each component in order to determine the component that is faulty.

Wiring Connector Electrical Check

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Illustration 1	g00765760
(1) GND terminal (2) HI terminal (3) LO terminal (4) Connector

1. Disconnect wiring harness connector (4) at the shift unit.

2. Set the axle speed range switch at LOW.

3. Connect a 24 volt test lamp to "GND" terminal (1) and "LO" terminal (3) and then connect the test lamp to the "GND" terminal (1) and HI terminal (2). The test light should light when the test light is connected to the "GND" terminal and the "LO" terminal. The test light should not light when the test light is connected to the "GND" terminal and the "HI" terminal.

4. Set the axle speed range switch at HIGH.

5. Repeat step 3. The test light should not light when the test light is connected to the "GND" terminal and the "LO" terminal. The test light should light when the test light is connected to the "GND" terminal and the "HI" terminal.

   Note: If the above test proves correct, power is present to the connector. Proceed to checking the motor housing cover.

Motor Housing Cover Electrical Check

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Illustration 2	g00765762
(1) Cover (2) Red wire (High range switch) (3) Black wire (Low range switch) (4) Green wire (Ground)

1. Remove motor housing cover (1) .

2. Disconnect the three lead wires at the cover.

3. Connect the positive lead of a 24 volt power supply to red wire (2) and the negative lead to green wire (4). The motor should turn.

4. Connect the positive lead to green wire (4) and the negative lead to black wire (3). The motor should turn.

   Note: In both tests, the motor should turn. If the motor turns, the circuit board and the motor are good. If the motor does not turn, the electrical connections for the housing cover could be faulty. Replace the cover or repair the cover.

   Note: If the cover is good and the motor does not turn, check the circuit board.

Electrical Check for the Circuit Board

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Illustration 3	g00765763
(1) Circuit board (2) Green wire (3) Black wire

1. Remove circuit board (1) and disconnect black wire (3) .

2. Connect the positive lead of a 24 volt power supply to the black wire and the negative lead to green wire (2) .

3. Apply 24 volts to the wires and note motor operation.

4. If the motor operates, the circuit board is faulty. If the motor does not operate the motor is faulty.

   Note: If the axle does not shift after the electrical tests on the electric shift, the components of the axle shift control could be faulty. Check the components of the axle shift control.