Procedure to Rework the Start Relay Magnetic Switch on Certain Underground Articulated Trucks {7499} Caterpillar

Underground Articulated Truck:

AD30 (S/N: DXR1-UP)

AD45B (S/N: CXM1-UP)

AD55 (S/N: DNW1-UP)

Introduction

This special instruction covers the procedure to rework the start relay magnetic switch, on certain Underground Articulated Trucks. This supplemental product support literature should be used with the appropriate Service Manual and the appropriate Parts Manual that is available for this standard machine.

Read the entire Special Instruction. Understand the information before you perform any procedures. Understand the information before you order any parts.

Safety Section

Work safely. Most accidents that involve product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs. A person must be alert to potential hazards. This person should also have the necessary training, skills, and tools in order to perform these functions properly.

Safety precautions and warnings are provided in this instruction and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons. Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard. Therefore, the warnings in this publication and the warnings that are on the product are not all inclusive.

Ensure that all personnel are safe when using a tool, procedure, work method, or operating technique not recommended by Caterpillar. Ensure that the product will not be damaged or the product made unsafe by the operation, lubrication, maintenance, or the repair procedures that are used.

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Personal injury or death can result from machine articulation or movement. Machine frames can move and a person can be crushed. Connect the steering frame lock between the front and rear frames before working on the machine. Before operating the machine, place the steering frame lock in the stored position. Failure to place the steering frame lock into the stored position before operating can result in loss of steering.

ReferenceSystems Operation Testing and Adjusting, RENR8534, "AD30 Underground Articulated Truck Machine Electrical System".

ReferenceSystems Operation Testing and Adjusting, RENR8562, "AD45B Underground Articulated Truck Machine Electrical System".

ReferenceSystems Operation Testing and Adjusting, RENR8507, "AD55 Underground Articulated Truck Machine Electrical System".

Parts Required

Removal Procedure

Note: Cleanliness is an important factor. Before the removal procedure, clean the exterior of the component thoroughly. Cleaning the exterior will help to prevent dirt from entering the internal mechanism.

1. Move the machine to a hard level surface away from operating machines and personnel.

2. Engage the parking brake. Place wheel blocks in front of the wheels and behind the wheels.

3. Stop the engine.

4. Connect the steering frame lock. Refer to Disassembly and Assembly, "Steering Frame Lock - Separate and Connect".

5. Turn the key start switch and the battery disconnect switch to the OFF position.

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Illustration 1	g03390880
(1) Starter harness (2) Starter motor

6. Disconnect two wires of starter harness (1) from starter motor (2) .

   Note: Retain nuts and washers for installation purposes.

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Illustration 2	g03390881
(1) Starter harness (3) Magnetic switch (4) Plug (5) Busbar (6) Circuit breaker

7. Disconnect red wire of starter harness (1) and busbar (5) from circuit breaker (6) .

   Note: Retain nuts and washers for installation purposes.

8. Remove and discard busbar (5) .

9. Disconnect white wire of starter harness (1) from magnetic switch (3) .

10. Disconnect plug (4) .

11. Remove and discard magnetic switch (3) .

    Note: Retain nuts, bolts, and washers for installation purposes.

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Illustration 3	g03390877
(1) Starter harness (7) Cable straps

12. Remove and discard starter harness (1). Where necessary, cut and discard cable straps (7) .

    Note: Retain clips for installation purposes.

Installation Procedure

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Illustration 4	g03390882
(8) 439-0816 Harness As (A) White wire (B) Red wire (C) White wire (D) Red wire

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Illustration 5	g03390883
(4) Plug (obscured) (6) Circuit breaker (8) 439-0816 Harness As (9) 254-3783 Magnetic Switch Gp (A) White wire (B) Red wire

1. Install 254-3783 Magnetic Switch Gp (9). Refer to Illustration 5.

   Note: Use bolts, nuts, and washers retained in ""Removal Procedure" ".

2. Install 439-0816 Harness As (8) white wire (A) onto magnetic switch (9) .

3. Install 439-0816 Harness As (8) red wire (B) onto circuit breaker (6) .

   Note: Use nuts and washers retained in ""Removal Procedure" ".

4. Connect plug (4) .

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Illustration 6	g03392960
(2) Starter motor (8) 439-0816 Harness As (C) White wire (D) Red wire

5. Install 439-0816 Harness As (8) white wire (C) and red wire (D) onto starter motor (2) .

   Note: Use nuts and washers retained in ""Removal Procedure" ".

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Illustration 7	g03393922
(8) 439-0816 Harness As (10) 1S-9593 Cable Straps

6. Secure loose wires using three 1S-9593 Cable Straps (10) and clips retained in ""Removal Procedure" ".

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Illustration 8	g03392964
(9) 254-3783 Magnetic Switch Gp (11) 438-5675 Wire As

7. Install 438-5675 Wire As (11) to 254-3783 Magnetic Switch Gp (9). Refer to Illustration 8.

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Illustration 9	g03392965
(6) Circuit breaker (11) 438-5675 Wire As (12) Orange wire

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Illustration 10	g03392966
(6) Circuit breaker (11) 438-5675 Wire As (12) Orange wire

8. Install 438-5675 Wire As (11) to circuit breaker (6). Use same terminal as orange wire (12). Refer to Illustration 9 and Illustration 10.

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Illustration 11	g03392967
(10) 1S-9593 Cable Strap (13) 4P-8134 Clip

9. Secure loose wires using 1S-9593 Cable Strap (10) and 4P-8134 Clip (13) .