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Western Star Trucks Electrical Schematics and Wiring Diagrams

Western Star Bodybuilder Book: Revision 3.1
Frequently Asked Electrical Questions

  • Question:How can I tell from the order if the truck has any body builder connections?
  • Answer:Look atsales code334and353to determine if supplemental body builder harness options where ordered with your truck.
  • Question:If there is a Body Builder option, what type of interface plug does the option have and wherewill it be located?
  • Answer:The 4700 offers blunt cut wires at the BOC with an access plate in the floor for body builder connections see page1A-13/14 and 1B-18/19. The 4800/4900/6900 offer body builderharnesses to the exterior BOC and the End of Frame with std plugs.  See page1B-14forschematics and details.
  • Question:Where can I find specific transmission information on the truck order and in the Body builderbook?
  • Answer:Truck specific Transmission specifications can be located in the truck order under sales code342a nd schematic information can be found using the sales codes found on page1B-4of this chapter of the body builder book.
  • Question:Can you obtain wiring diagrams for specific options for serial numbers and any informationon dealer optionally installed features?
  • Answer:Specific schematic information can be obtained by serial number is available to our dealers on line via PartsPro and EZ wiring. Use page1B-4of this chapter to locate the modulelocation information.

All EPA 2010 LHD Models
Chassis Harness Max Complexity Harness
New electrical systems for 2010 will be shown using a Max Complexity harness layout L06-82534. This new diagram system provides all possible connections that are available on one single diagram. This information provides the connector part number and the Sales Code and or Module number that the option and schematic detail can be found.

How to use this diagram system
Use the diagram to locate where on the chassis the connections will be located.

Remote Fast Idle Circuits

Western Star Trucks Electrical Schematics and Wiring Diagrams
  1. Wires 440D, 440F & 440E are spliced into the cruise switch wiring in the dash and run though the front wall at a 40 pin connector pins 11, 9 & 10 respectively.
  2. Harness P/N A06-74578-000 ties into the 40 pin connector on the engine side of the front wall and ends in a 6 pin connector with wires 440D, 440F, 440E & 440G. (This harness is approximately 51" long.)
  3. Harness WWS 87208-3428-210 connector PS19_0 will connect to the 6 pin connector and have enough length to route to the end of frame, i.e. this harness is 210" long.

4700 Body Builder Cab Access Port
Accessing the cab on the 4700 SF and SB is quick and simple using the floor access plate at the back of the cab. look for cuts in the floor mat at the center of the cab under this flap is a cover plate which gives you structurally designed access from the chassis into the cab. Plates can be removed from the unit and mounted at a workbench if desired for better sealing of cab mating harness.

Speed Sensor Connections Interface
Adding addition equipment such as the vehicle speed when installing a salt/sander spreader with a controlled flow rate at different speeds can be accomplished by adding a second.

adding a second speed sensor to the rear bearing cover of the transmission after delivery. You will need to purchase the following parts
P/N FUL K4148 (two wire speed sensor),
P/N FUL X8 0801M (mounting screw)
P/N A06-26585-000 (adapter harness)
to connect this signal to your system simply cut off the access end of the adapter harness and wire to body harness.