Freightliner Electrical Wiring Diagrams and Schematic Diagrams

Circuit diagramthe location of the connectors on the framecable arrangement of sensor connectors on the engine

Vehicle identification

Car access

Electrical system

Instruments and controls

Governing bodies

Seats and restraints

Climate control

Cab specifications

Mercedes-Benz engines

Detroit Diesel engines

Caterpillar engines

Air brake system

Engine brake Manual gearboxes and hydraulic clutch

SmartShift Freightliner automated gearboxes



Fontaine fifth wheel coupling

Coupling device for Holland trailer

Headlight adjustment

General specifications

General Maintenance Information



Frame and its components


Front axle

Rear axle

Cardan drive

Brake system


Exhaust system

Heater and air conditioning

Wheels and tires

Freightliner Wiring Diagrams

The Freightliner wiring diagrams are divided by system function. This allows

for many different options or accessory systems to be installed on the same

model truck. Examples for this section are drawn from the diagram below

Freightliner Valve Park Brake System.pdf
Adobe Acrobat Document 231.8 KB

Portable Network Image Format 99.6 KB
Aeromaster on Freightliner Chassis - Wir
Adobe Acrobat Document 1.5 MB
Freightliner DDEC II and III Wiring Diag
Adobe Acrobat Document 993.1 KB

Checking and cleaning the trailer cable one.

Disconnect the trailer electrical cables from the outlets in the cab.


Inspect the cables and connectors for corrosion and clean if necessary. If the outlet is too corroded to clean, replace it. Freightliner also recommends replacing the wiring harness of the outlet if corrosion has entered the wires and connectors inside the outlet.

IMPORTANT: When using an aerosol cleaner to remove corrosion, be careful to protect any surrounding painted surfaces.


Apply lithium-based dielectric grease to the inside of the connectors, such as Lubriplate FLP DS-ES.


Connect the cables.

Comments: 10
  • #10

    Justin (Thursday, 12 January 2023 00:04)

    Looking for ignition schematic and ABS schematic for 2005 freightliner columbia VIN U74946 with c13 engine.


  • #9

    Darlings Boatworks (Tuesday, 27 December 2022 14:29)

    Where can I download a wiring diagram for a 2007 M2 business class.

  • #8

    abe (Saturday, 17 December 2022 02:29)

    Hi i need a tail light wiring diagram for a 2016 freightliner m2 106 hydraulic brake

  • #7

    Troy (Wednesday, 09 November 2022 06:10)

    Could I please get the wiring diagram for a 1/1995 fL112

  • #6

    Scott Ballard (Sunday, 06 November 2022 16:18)

    I’m after wiring diagram for bunk hvac on a 2016 freightliner Coronado

  • #5

    Mihkel (Tuesday, 04 October 2022 23:45)

    I'm after wiring diagram for a 2005 argosy

  • #4

    Ashley (Saturday, 24 September 2022 20:51)

    Need a wiring diagram for a 2005 century freightliner

  • #3

    Martha (Thursday, 02 June 2022 00:00)

    I need the wiring diagram on a 2006 Freightliner FLD 120

  • #2

    Randall (Friday, 27 May 2022 18:34)

    Need wiring diagram for the hood to fire wall on a 2001 fl80

  • #1

    Dillard Kersey (Sunday, 14 November 2021 21:05)

    i need the wiring diagram