SBW54-075

54-075
Lengthening the Backup Light Harness
Constellation
Heritage
> 4700 Models
4800 Models
> 4900
> 5700
5900
> 6900
Western Star
Service Bulletin
Models
Models
Models
Models
General Information
Though the back-up light harness is long enough to connect to the backup light switch, it may be short enough
that the wire seals in the connector can be stressed. Moisture entering through the seals can cause corrosion,
resulting in a bad connection and/or failure of the switch.
As a result, backup lights and, if equipped, the backup alarm, may not function when the vehicle is shifted into
reverse.
All Western Star vehicles built through March of 2019 using the back light switch (POL21 465 or POL21 566)
may be affected.
Parts
The parts required for this procedure are shown in Table 1.
Parts Table
Part Name
Light Switch Jumper Harness
Part Number
A66-19642-000
Quantity
1
Table 1, Parts Table
Work Instructions
1. Park the vehicle on a level surface, apply the parking brakes, and shut down the engine. Chock the tires.
2. Disconnect the batteries.
3. Locate the backup light switch on the transmission and, as needed, remove the clipping points for access.
Unplug the connector from the backup switch. See Fig. 1.
03/20/2020
f547144
Fig. 1, Connector Unplugged
4. Cut off the backup harness connector where the wires enter the connector. See Fig. 2.
Western Star Service Bulletin, 04/09/2020
Page 1
54-075
Lengthening the Backup Light Harness
Western Star
Service Bulletin
Constellation
Heritage
> 4700 Models
4800 Models
> 4900
> 5700
5900
> 6900
Models
Models
Models
Models
2
3
4
1
03/20/2020
f547145
1. STA-DRY Butt Connectors
2. Stripped Wires on Light Switch Jumper Harness
(A66-19642-000)
3. Stripped Wires on Old Harness
4. Light Switch Jumper Harness (A66-19642-000)
Fig. 2, New Light Switch Jumper Harness
5. Connect the new jumper harness (A66-19642-000) using two STA-DRY butt connectors (PHM 1 1863). See
Fig. 3.
Page 2
Western Star Service Bulletin, 04/09/2020
54-075
Lengthening the Backup Light Harness
Constellation
Heritage
> 4700 Models
4800 Models
> 4900
> 5700
5900
> 6900
Western Star
Service Bulletin
Models
Models
Models
Models
03/20/2020
f547146
Fig. 3, STA-DRY Butt Connectors, Crimped
6. Using a heat gun, carefully heat shrink the butt connector.
7. Protect the butt splices and exposed wiring with an appropriate harness wrap.
8. Connect the new connector at the backup light switch, making sure the wires enter the connector as
straight as possible and are not stressed.
9. Secure the backup light harness as needed using the original clipping points or tie straps.
10. Connect the batteries.
11. Test the operation of the backup and lights, and, if equipped, the backup alarm.
Warranty
This procedure is warrantable only if the described condition exists and the repair is performed within the
applicable base or extended coverage warranty period. If a failure is not found, this procedure is considered
preventive and warranty does not apply.
Normal warranty applies. See Table 2 for OWL VMRS codes and labor allowance information. Enter this service
bulletin number in the Service Bulletin # field.
Western Star Service Bulletin, 04/09/2020
Page 3
54-075
Lengthening the Backup Light Harness
Western Star
Service Bulletin
Primary Failed Part
Harness, Back Up
Light Switch
Constellation
Heritage
> 4700 Models
4800 Models
Component
Code
034-002-035
> 4900
> 5700
5900
> 6900
OWL VMRS Codes and Labor Allowance
Correction
SRT Code
Description
Code
Jumper, Backup Switch Service
03
35H-5001A
Harness, R/R
Models
Models
Models
Models
Time: Hours
0.3
Table 2, OWL VMRS Codes and Labor Allowance
Page 4
Western Star Service Bulletin, 04/09/2020