Guidelines for Repairing or Replacing an Electrical Harness
> Recreational Vehicle
> School Bus
> Shuttle Bus

54-048

Freightliner Custom Chassis
Service Bulletin

> Walk-In Van
> S2

Description of Revisions: This bulletin replaces the version dated
February 2016. Sewing Seam Ripper tool part and TwistTube®
part list are added in the bulletin and convolute tubing has been
removed.

General Information
Use the guidelines in this bulletin to determine if a damaged electrical harness should be repaired or replaced.
Refer to the wiring section in Group 54 of the applicable workshop manual for detailed wire repair instructions.
Table 1 describes general guidelines for repairing or replacing a harness. There may be cases when more than
one factor determines the course of action. For example, repairing a harness is recommended if shipping times
for the replacement harness exceed one week. However, replacement may be the only option if damage to the
harness is too extensive.

NOTE: When a harness is repaired, the source of the damage must also be identified and repaired.
Table 2 is a quick-reference for specific wire and terminal conditions.

IMPORTANT: Damaged connectors and seals can be replaced without replacing the harness. A drag
test should be performed to make sure that the terminal can retain proper tension to the mating
terminal. Refer to "Terminal Drag Test" in this bulletin for instructions. Discolored wires or melted
insulation should be replaced before any other repairs are performed on the harness.
Repairing or Replacing a Harness
Repair
Less than 20% of the harness is damaged.
If the wire damage is greater than 6 inches (15 cm), an
overlay harness can be added to replace the section of
damaged wire.
Wire is smaller than 12-gauge.
The harness is not readily available, or shipping will take
longer than one week.
Wire insulation is cracked due to excessive heat from an
external source. Repair is recommended if the damage is
isolated to one section of the wire.
There is a clean cut to the wire, corrosion is wicked no more
than 1 inch (2.5 cm) from the terminal end. If the damaged
area is over 6 inches (15 cm), the harness can be repaired
by adding overlay wiring over the damaged area.

Replace

More than 20% of the harness is damaged.

Wire is 12-gauge or larger.
The harness can be obtained in less than a week.
Wire insulation is cracked due to age, or damage is
extensive and spread throughout the wire.

The harness is proprietary, such as a datalink with sheathing
NOTE: If damage exceeds 1 inch (2.5 cm) from the terminal over a twisted pair, or a WABCO sensor and solenoid
wiring.
end, a quality repair may require adding a jumper wire to
create enough slack in the wire. If adding extra splices
stretches the wire too tightly it can degrade the integrity of
the harness.

Freightliner Custom Chassis Service Bulletin, 02/04/2020

Page 1

54-048

Guidelines for Repairing or Replacing an Electrical Harness

Freightliner Custom Chassis
Service Bulletin

> Recreational Vehicle
> School Bus
> Shuttle Bus

> Walk-In Van
> S2

Repairing or Replacing a Harness
Repair
Replace
Two harnesses are affected. For example, M2 24 pin lever
lock connector (23-13144-010 and 23-13144-009) is
corroded on both sides. Also, if the harness has minimal
corrosion wicked up the wire, the connectors can be reExtensive damage to the harness caused by foreign material
pinned.
such as DEF fluid, diesel fuel, or road/deicer fluid.
If the damaged area is over 6 inches (15 cm), the harness
can be repaired by adding overlay wiring over the damaged
area.
Table 1, Repairing or Replacing a Harness
Wire Damage Quick Reference
Description
Remedy
Kinked Wire
Repair
Melted Insulation, Major.
Replace
Melted Insulation, Minor
Repair
Worn or Missing Insulation. See Fig. 1.
Repair
Discolored or Cracked Insulation, Major.
Replace
See Fig. 2.
Discolored or Cracked Insulation, Minor.
Repair
Datalink, Twisted Wire
NOTE: If only the terminals are damaged,
the terminals can be replaced without
replacing the twisted pair.
Corrosion in the Wire*
Corrosion in the Connector
Failed Terminal Pair Drag Test
Molded Cable†

Replace

Repair
Repair
Replace
Terminal
Replace

* Corrosion is wicked no more than 1 inch (2.5 cm) from the terminal end,
and no corrosion is wicked into the wire.
† An example is Meritor WABCO ABS sensor wiring.

Table 2, Wire Damage Quick Reference

How to Identify a Repairable Wire

Page 2

Freightliner Custom Chassis Service Bulletin, 02/04/2020

Guidelines for Repairing or Replacing an Electrical Harness
> Recreational Vehicle
> School Bus
> Shuttle Bus

54-048

Freightliner Custom Chassis
Service Bulletin

> Walk-In Van
> S2

12/16/2014
02/16/2015

f546121

f546138

Fig. 2, Insulation Discoloration, Major
Fig. 1, Worn Insulation, Major

See Table 3 to identify a repairable wire.

Condition

Corroded Terminal

Identifying a Repairable Wire
Description

Example

If there is no further corrosion in the
wire, and it is not blackened from
corrosion, the wire can be repaired
by cutting off the corroded terminal
and stripping away the wire
insulation. A new terminal can then
be installed and inserted into the
connector.
NOTE: If the repair causes the wire
to be pulled tight, or results in
tension at the connector, a short
piece of wire and new terminal can
be added to reduce the tension.
Otherwise, all terminals must be
replaced.

A
10/29/2014

f546107

A. Corroded terminal.

Freightliner Custom Chassis Service Bulletin, 02/04/2020

Page 3

54-048

Guidelines for Repairing or Replacing an Electrical Harness

Freightliner Custom Chassis
Service Bulletin

Condition

Corroded Wire

> Recreational Vehicle
> School Bus
> Shuttle Bus

Identifying a Repairable Wire
Description

> Walk-In Van
> S2

Example

Corroded wires can be repaired by
cutting out the damaged section.
The wire needs to be cut until only
clean wire is found for repair. It may
be necessary to add a jumper wire
to create slack and avoid wire
tension. Refer to the instructions in
this bulletin to install a jumper wire.
The example shows a small amount
of corrosion at the end of the wire.

Cut Wire (clean)
or
Worn Insulation

12/16/2014

f546117

10/29/2014

f546106

If the wire shows no sign of
corrosion, the wire can be repaired
with a splice kit.

Table 3, Identifying a Repairable Wire

Broken or Corroded Wires
Whether or not a broken or corroded wire, or cracked insulation should be repaired or replaced depends on the
extent of the damage.
A broken wire can be soldered together only if enough slack remains to avoid wire tension. If there is not
sufficient slack, a new section of wire must be soldered between the two broken ends. This technique can also
be used with small sections of corroded wire. Overlay wiring can also be used in the damaged area, however
the entire harness must be replaced if the corrosion exceeds 6 inches (15 cm).
If terminals are corroded at the connector, the terminal can be replaced. However, the entire wire must be
overlayed if corrosion exceeds 6 inches (15 cm). A jumper wire can be used in the case, if necessary.

Installing a Jumper Wire
1. Remove the terminal from the connector.
2. Cut out the damaged section of wire.

Page 4

Freightliner Custom Chassis Service Bulletin, 02/04/2020

Guidelines for Repairing or Replacing an Electrical Harness
> Recreational Vehicle
> School Bus
> Shuttle Bus

54-048

Freightliner Custom Chassis
Service Bulletin

> Walk-In Van
> S2

3. Crimp and solder the new terminal with a new seal (if required) on to the new section of wire.

NOTE: Make sure the wire is the same gauge and quality as the wire being replaced.
4. Insert the terminal into the connector. See Fig. 3.
5. Run the wire along the harness up to the section of wire that is being replaced. See Fig. 4.
6. Splice the wires using a Daimler splice kit ESY ES66 404, or Phillips STA-DRY® Crimp and Solder
connector parts. See Fig. 5. Refer to Table 4 for a list of connector parts.
7. Inspect the harness and make sure there is enough slack. See Fig. 6.
8. Wrap the harness with TwistTube® fiber wrap. See Fig. 7.

12/16/2014

f546126

Fig. 4, Section of Wire to be Replaced
12/16/2014

f546120

Fig. 3, Terminal Inserted Into the Connector

Freightliner Custom Chassis Service Bulletin, 02/04/2020

Page 5

54-048

Guidelines for Repairing or Replacing an Electrical Harness

Freightliner Custom Chassis
Service Bulletin

> Recreational Vehicle
> School Bus
> Shuttle Bus

> Walk-In Van
> S2

A

02/16/2015

f546135

Fig. 5, Splicing the Wires

12/16/2014

f546124

A. The wire should be slack so that there is no
tension.
Fig. 6, Slack in the Connector