Procedure To Repair Or Replace 383-8828 Engine Wiring Harness On Certain D6T Track-Type Tractors {1000, 1408} Caterpillar

Track-Type Tractor

D6T (S/N: CR31-UP; CG81-UP; SGA1-UP; RAD1-UP; STE1-UP; MEL1-UP; WRN1-UP; KMR1-UP; WES1-UP; SGT1-UP; TMY1-UP; HTZ1-UP)

Introduction

Illustration 1	g06110589

The 40-pin connector of 383-8828 Engine Wiring Harness that is connected to the Clean Engine Module (CEM) may be routed closer than intended to the evaporator air conditioning hoses. The hoses may wear through the insulation of the wires causing CEM fault codes and system issues resulting in potential CAN Data Link (CDL) Codes and Descriptions. The following codes (non-inclusive) have been reported: E1389 Aftertreatment #1 SCR Operator Inducements and E1239 DPF #1 Conditions Not Met for Active Regeneration. This special instruction provides direction for replacing or repairing the engine harness on certain D6T Track-Type Tractors.

Do not perform any procedure in this Special Instruction until you have read the information and you understand the information.

Safety Section

Required Parts

Installation Procedure

Repair Installation Procedure

If the engine harness can be repaired, Table 2 has related part numbers that can be ordered as needed.

Note: Caterpillar recommends repairing the harness when there is minimal damage to the wire or harness. For instance, if the insulation is worn off on only a few wires. Replacement of the harness is recommended whenever there is significant indications of heat damage, wire strand failure, or an excessive number of wires have been worn.

Illustration 2	g06110603
Example of a harness that could be repaired.

Illustration 3	g06110606
Example of a harness that has been repaired.

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Illustration 4	g06110608

1. For harness repair open the left engine door and remove the rear left engine enclosure and lower left engine enclosure frame.

2. As needed, cut, and splice any problematic wires.
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   Illustration 5	g06110615
   (2) 7X-7729 Washer (3) 8T-4121 Hard Washer (4) 8T-4186 Bolt (5) 124-6524 Spacer (6) 352-3968 Clip

3. If the hardware shown in Table 3 is not already in place from the factory, do the following to secure the harness away from the AC lines. Refer to Illustration 6 for details.

4. Remove the original bolt, washer, tie wrap mounts, and the spacer from the CEM plate.

5. Assemble the new ladder clip (6) with the washer (3) and bolt (4). Stack spacers (2) and (5) on the back of the ladder clip to make sure that the new clipping points are further rearward on the tractor.
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   Illustration 6	g06110757
   (1) 7K-1181 Cable Strap (7) 353-7957 Grommet

6. Use one tie strap (1) to secure the branch of the wire harness that has the 40-pin connector. The 40-pin connector should be secured closer to the front of the tractor. Place grommet (7) around the hood branch of the wiring harness. Then secure the grommet and harness to the ladder clip with tie strap (1). The hood branch should be secured closer to the rear of the tractor.

Replace Installation Procedure

Illustration 7	g06110618
Example of a harness that should be replaced.

If the engine harness is determined to be beyond repair and must be replaced, follow the steps below.

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Illustration 8	g06110608

1. For harness replacement, open the left and right engine area. Remove rear engine enclosures and lower engine enclosures and frames.

2. Remove the floor mat and floor plates from the cab for access into the manhole to the harness around the torque converter and pumps.

3. Remove or hinge the rear belly guard for access to the harness around the torque converter & pumps.
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   Illustration 9	g06110640
   View of engine harness from left track.

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   Illustration 10	g06110647
   View of engine harness below left track line.

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   Illustration 11	g06110655
   View of engine harness in manhole (implement pump is shut off for clarity).

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   Illustration 12	g06110664
   View of engine harness form operator seat.

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   Illustration 13	g06110669

   Note: For the machines in Table 5, the platform might need to be lifted slightly to access the clips securing the harness at the left rear CEM mount. The hardware can run into the platform before the harness is free. Loosen the platform mounting hardware and the hood mounting hardware and lift the platform approximately 25 mm (1 inch). The platform can be secured with blocks to allow access to the hardware. New hardware is required to update the engine harness clipping in this area.

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   Illustration 14	g06110797
   View of engine harness hardware from left side that needs to be removed, possibly with the cab/platform lifted, on left rear CEM mount. (Left fender turned off for clarity.)

4. Remove the failed engine 383-8828 Wiring Harness. View Illustrations 9 through 14 to help clarify the existing routing. Retain the hardware to reinstall the new harness.
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   Illustration 15	g06111036

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   Illustration 16	g06111038

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   Illustration 17	g06111046
   New engine harness and bracket near rear, left CEM mount (2) 495-1121 Bracket As (3) 8T-4195 Bolt (4) 8T-4121 Hard Washer

5. Install new engine wiring harness (1). Reuse hardware except in the following locations.

6. Remove old 390-1709 Bracket As. Install new bracket assembly (2) with two bolts (3) and two washers (4). The new bracket assembly will secure the new harness routing to the front of the CEM.
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   Illustration 18	g06111094
   New engine harness hardware near lower end of rear, left CEM mount

7. At the lower end of the rear, left CEM mount install stud bolt (5) short end into the casting. Install new spacer (6), clip (7), clip (8), and grommet (9). Secure the DEF line with washer (4) and nut (10).

8. Once the harness has been fully reinstalled, re-torque the platform bolts if applicable. Torque bolts to 900 ± 100 N·m (664 ± 74 lb ft).

Illustration 19	g06111106
New engine harness at lower left of engine

Illustration 20	g06111118
Left-hand side engine compartment harness views

Illustration 21	g06111121
View of engine harness in manhole (implement pump shut off for clarity)

Illustration 22	g06111125
View of engine harness from operator seat

Illustration 23	g06111129
Engine harness clipping relative to alternator cable at the front of the manhole

Illustration 24	g06111144
Right-hand side compartment harness view at alternator