2006/03/27 Caterpillar

Backhoe Loader:

420D (S/N: BLN1-UP)

430D (S/N: BML1-UP)

The 183-4738 Work Tool Harness As runs along the loader arm and to the solenoid for the quick coupler. The 183-4738 Work Tool Harness As has reports of failures that are associated with open or short circuits. Failures appear to be concentrated on 420D IT (S/N: BLN) and 430D IT (S/N: BML) machines.

Illustration 1	g01256725

The harness in Illustration 1 did not have the cable strap gun set to the correct tension. Excessive tension will crush the harness and excessive tension will pinch the wires. This will cause the wires to fail.

The harness will need to be replaced with a new harness.

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Illustration 2	g01256746

1. Disconnect the 183-4738 Work Tool Harness As (1). Cut the 3S-2093 Cable Straps (2) .

2. Remove the old 183-4738 Work Tool Harness As (1) .

3. Install a new 183-4738 Work Tool Harness As (1). Route the harness along the loader arm. Use the 3S-2093 Cable Straps in order to loosely secure the harness. Refer to Illustration 2. Connect the electrical connections .

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Illustration 3	g01256723

4. Use the cable strap gun (4) in order to secure the new 3S-2093 Cable Straps (2) .

   Note: In order not to crush the harness, set the cable strap gun to the proper tension.