Land Rover Defender: Wiring Harness - Most Network Harness Repair

If a fiber optic cable is damaged, it must not be repaired and must be replaced with a new cable.

Replacement fiber optic cables can only be made using the approved repair equipment and components.

The approved repair kit contains the specially designed fiber optic conductor strippers. The cutters are used to prepare 2.3 mm (0.09 inch) fiber optic cable for the installation of the brass fiber optic conductor contact. The fiber optic conductor contact crimping pliers must then used be used to crimp the brass contact to the fiber optic conductor core. The approved crimping pliers supply the appropriate pressure to the brass contact to make a secure contact, but not damage the conductor core.

The cut face of the fiber optic core must be protected from damage and contamination at all times.

CAUTION: Fiber optic cables have a maximum bending radius 25 mm (0.98 inch) and must not be kinked or excessively bent.

The performance of fiber optic cables is very dependant upon the quality of the cut surface at connections and to the bending radius of the cables.

MOST HARNESS REPAIR COMPONENTS AND TOOLS

List of Parts

NOTE: Repair components can be ordered through the JLR parts ordering system.

Fiber Optic Conductor Stripper

Fiber Optic Conductor Stripper Jaw Positions

1. Fiber Optic Cable Cutter
2. Fiber Optic Cable Insulation Stripper
3. Fiber Optic Core Cutter

Fiber Optic Core Cutter Locking Screw

The fiber optic core cutter has a locking screw to protect the cutter wheel when in transit or not in use. A hexagonal key is supplied in the MOST repair kit to release the locking screw.

NOTE: Tighten the transportation locking screw after use.

Fiber Optic Core Cutter Remaining Cut Indicator

The fiber optic core cutter can be used for approximately 1260 cuts. The indicator line on the remaining cut indicator window only becomes visible when the fiber optic core cutter has 150 cuts or below available.

NOTE: When the fiber optic core cutter has reached the maximum allowed cuts, the cutter will become locked and the fiber optic conductor stripper must then be renewed.

Before using the fiber optic conductor core cutter, make sure it has enough cuts remaining to complete the repair process by viewing the remaining cut indicator.

Fiber Optic Conductor Contact Crimping Pliers

A small amount of effort is required to operate the fiber optic conductor contact crimping pliers and secure a fiber optic conductor contact to the fiber optic conductor core.

The new fiber optic conductor contact is placed into the cramping mechanism in the head of the pliers. The locking arm is repositioned to hold the conductor contact securely in position. The locking arm must locate on to the retaining pin.

The prepared end of the fiber optic core is then inserted into the new conductor contact.

The fiber optic core and conductor contact must be pushed and held against the spring pressure in the cramping mechanism. The grips of the fiber optic conductor contact crimping pliers are then be closed, cramping the conductor contact to the conductor core.

NOTES:

• Only use the approved fiber optic conductor contact crimping pliers to cramp a new conductor contact.
• A conductor contact must only be cramped when using the fiber optic conductor contact crimping pliers.

The cramping mechanism inside the head applies the appropriate pressure to the conductor contact at 4 points. This makes a secure contact and does not damage the conductor core.

When the new conductor contact has been cramped to the fiber optic core do the following. Make sure the fiber optic core end sits 0.01 mm (0.00039 inch) to 0.1 mm (0.0039 inch) below the height of the conductor contact end.

NOTE: Make sure the fiber optic conductor lead contact remains clean and protected at all times. Install a fiber optic conductor contact protective cap.

MOST Repair Tools

NOTE: Replacement repair equipment can be ordered from the equipment workshop website; refer to the Replacement Repair Equipment in the Introduction section.

MOST HARNESS REPAIR PROCEDURE

The MOST connector(s) have an anti-backout device which prevents the contact from being released from the connector. The anti-backout device must be released before attempting to remove the terminal from the connector.

The anti-backout devices require a special tip to release the device. Please refer to the ERL for the correct tool(s) to use.

The illustration shows an example of a common style of extraction tool being used on a MOST connector(s). Care should be exercised to avoid further damage when removing the terminals from the connector.

CAUTIONS:

• Before releasing the fiber optic cable from the connector housing, mark the IN/OUT assignment of the fiber optic cable.
• Make sure a protective cap is installed on all disconnected MOST connectors and fiber optic cables. The protective cap prevents contamination and damage to the exposed end faces of the fiber optic cable.

MOST Connector Terminal Extraction

MOST Harness Repair Process

1. Confirm the length of fiber optic conductor lead required to create a new fiber optic cable. Cut the fiber optic conductor lead to the required length using the fiber optic cable cutter.

2. Open the fiber optic conductor stripper jaws and insert the fiber optic conductor lead up to the edge of the jaws.

3. Close the fiber optic conductor stripper jaws (1) and carefully pull the fiber optic conductor lead (2) to remove the protective casing.

NOTE: Make sure the protective casing of the fiber optic conductor lead sits against the fiber optic conductor cutter jaw stop.

4. Open the fiber optic conductor stripper jaws and insert the fiber optic conductor lead fully into the fiber optic conductor cutter slot. Close the fiber optic conductor stripper jaws.

5. Pull the fiber optic conductor core cutter lever (1) to move the cutting wheel (2) and cut the fiber optic conductor core.

NOTE: The end of the fiber optic core has now been prepared for the fitting of a brass contact.

6. Open the fiber optic conductor stripper jaws and remove the fiber optic conductor lead.

NOTE: Make sure the fiber optic conductor core end remains clean at all times.

7. Place fiber optic conductor stripper and fiber optic conductor lead to 1 side.
8. Open the fiber optic conductor contact pliers and reposition the conductor contact locking arm to the open position.

NOTE: Make sure the locking arm locates on the retaining pin when in the closed position.

9. Insert a onductor contact (1) into the fiber optic conductor contact crimping jaws and reposition the conductor contact locking arm to the closed position (2).

10. Insert the prepared end of the fiber optic conductor lead into the conductor contact.

CAUTION: Make sure the fiber optic conductor lead is pushed in and held against the spring loaded stop when closing the fiber optic conductor contact pliers. This sets the core to the correct depth in the brass connector. Failure to follow this instruction may result in the fiber optic conductor cable malfunctioning.

11. Push the fiber optic conductor lead fully into the conductor contact and close the fiber optic conductor contact pliers.
12. Open the fiber optic conductor contact pliers and reposition the conductor contact locking arm to the open position.
13. Remove the fiber optic conductor cable from fiber optic conductor contact pliers.
14. Place fiber optic conductor contact pliers to 1 side.

CAUTION: Make sure the conductor contact has been correctly installed to the fiber optic conductor core. Failure to follow this instruction may result in the fiber optic cable malfunctioning.

NOTES:

• The fiber optic core end must sit 0.01 mm (0.00039 inch) to 0.1 mm (0.0039 inch) below the height of the conductor contact end.
• Make sure the fiber optic conductor contact remains clean at all times.

15. Visually inspect the conductor contact for correct installation to the fiber optic core.

• Make sure the conductor contact has been visibly crimped at 4 points.
• Pull the conductor contact by hand to make sure it is secure.
• Make sure the end of the fiber optic core sits below the height of the new conductor contact end.
• Install a fiber optic conductor contact protective cap.

16. Repeat steps 2 to 15 and install a conductor contact to the opposite end of the fiber optic conductor cable.
17. Measure between the conductor contact ends of the new fiber optic cable. Using a suitable tool cut a length of new protective corrugated tubing to the required length.

18. Install the fiber optic cable into the corrugated tubing.

1. Place the fiber optic cable inside the fiber optic conductor cable installation pliers.
2. Insert the fiber optic conductor cable installation pliers into the corrugated tubing.
3. Move the fiber optic conductor cable installation pliers down the length of corrugated tubing and install the fiber optic cable.

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