2019 Freightliner Cascadia Trailer Light Fuse Location -
Many 2019 Cascadias have a second set of trailer-related fuses inside the battery box on the driver’s side frame rail, just behind the front tire.
To access:
Here you will find:
Step 1: Pop the Hood Release the hood latches and secure the hood in the upright position.
Step 2: Find the Black Box Look at the firewall (the wall between the engine and the cab) on the driver’s side. You will see a large black plastic box with a grey lid. It usually has two metal release clips on the sides.
Step 3: Remove the Lid Unlatch the two metal clips and lift the lid. Pro tip: Look on the underside of the lid. Freightenger is good about printing the diagram right there on the plastic.
Step 4: Identify the Exact Fuses For a 2019 Cascadia, you are looking for three specific fuses, usually grouped together:
Note: Some PDM layouts use slot #63 for the trailer stop lamp circuit.
Disclaimer: Freightliner changes wiring diagrams based on build date and specific VINs. Always trust the diagram printed on your specific truck's fuse cover over generic guides.
Finding the fuse for trailer lights on a 2019 Freightliner Cascadia
depends on whether you have the classic body or the "New Cascadia" (P4) model, as the locations changed significantly during that production year. Key Locations for Trailer Light Fuses
For most 2019 models, the fuses and relays are split between three main areas:
Passenger Side Dash (Main Location): The primary fuse panel is behind the glove box or a "pull-off" panel in front of the passenger seat. To access it: Open the glove box or pull the panel marked "PULL".
You may need a T-25 Torx bit for older configurations, but many 2019 models use simple snap-on covers.
A detailed diagram is usually printed on the inside of the cover.
SAM Chassis (Under the Hood): If you are missing marker lights, check the SAM Chassis module. This is located on the driver-side firewall inside the engine compartment. On some newer 2019 units, this module manages the trailer lights through computer logic rather than traditional individual fuses.
Vehicle Power Distribution Module (VPDM): Located under the passenger-side dash cover or beneath the passenger seat. This panel contains high-amp fuses and main power relays. Troubleshooting Common Light Issues New 2019 Freightliner Cascadis Truck Fuse & Relay Location 2019 freightliner cascadia trailer light fuse location
Finding the trailer light fuse location on a 2019 Freightliner Cascadia can be tricky because the "New Cascadia" model (P4) transitioned many traditional fuse functions into advanced computer modules. Primary Fuse Locations
There are three main areas where you will find fuses and relays on a 2019 model:
Behind the Glove Box (In-Cab SAM): The primary interior fuse panel is located behind the passenger-side glove box. You must remove the glove box (often requires a T-25 Torx driver) to access the SAM Cab module.
Engine Compartment (SAM Chassis): The SAM Chassis module is typically located on the driver-side firewall under the hood. This module manages most exterior lighting and chassis functions.
Passenger Seat Base (Power Distribution Module): A separate Power Distribution Module (PDM) is often found under the front of the passenger seat; pull the panel marked "pull" to reveal it. Key Fuses for Trailer Lights
On the 2019 "New Cascadia," traditional fuses for trailer lights are often replaced by solid-state "smart" logic in the SAM modules. However, you should still check the following: JustAnswerhttps://www.justanswer.com
2020 Freightliner Cascadia Trailer Marker Light Fuse Location
The fuses you're looking for are located on a fuse panel behind the glovebox on the passenger side. YouTube·Big Rig Fixhttps://www.youtube.com New 2019 Freightliner Cascadis Truck Fuse & Relay Location
For a 2019 Freightliner Cascadia (Gen 2/New Cascadia), the trailer light control system has shifted from traditional dedicated fuses on the firewall to an integrated electronic control system. Primary Fuse and Module Locations
In the 2019 model year, most lighting functions are managed by the SAM (Signal Activation and Modulator) Chassis and SAM Cab modules.
SAM Cab (Main Internal Panel): Located behind the glove box on the passenger side. Accessing this involves removing the glove box (typically requiring a T-25 Torx driver) and a protective rain guard.
Dash Panel/Electronics Vault: On some newer Cascadia models, there is an accessible panel on the passenger side dash marked "PULL" that reveals a fuse and relay compartment.
SAM Chassis (Engine Compartment): This module is located on the driver's side firewall under the hood. It contains electronic controls for most chassis electrical systems.
Vehicle Power Distribution Module (VPDM): A red box located on the passenger side firewall under the hood. It provides power to the SAM modules. Specific Trailer Light Issues
For 2019 and newer Cascadias, individual trailer light circuits (marker, turn, stop) often do not have traditional fuses. Instead, they use electronic relays within the SAM Chassis that automatically reset once a short circuit is cleared and the ignition is cycled.
Trailer Marker/Running Lights: These are often controlled by the SAM Chassis logic. If they are not working, check for a short in the trailer or cord, then cycle the key. Many 2019 Cascadias have a second set of
Trailer Auxiliary Power: If specifically missing auxiliary power, check fuses 61A and 61B in the SAM Cab module.
Trailer ABS: For ABS-related issues, check fuses F43, F25, and F26 in the passenger side fuse box.
These videos demonstrate how to access the various fuse and relay compartments in a new-generation Freightliner Cascadia: New 2019 Freightliner Cascadis Truck Fuse & Relay Location Big Rig Fix
Finding the trailer light fuse on a 2019 Freightliner Cascadia
can be tricky because this model year often utilizes a Single SAM (sSAM) system where many lighting circuits are logic-controlled and may not have a traditional dedicated fuse. Primary Fuse Box Locations
If your 2019 Cascadia uses traditional fuses for trailer functions, they are typically found in these three areas: Passenger Side Dashboard (SAM Cab):
Location: Behind the removable panel in front of the passenger seat or inside the glovebox area.
Access: Look for a panel labeled "PULL". Inside, you will find a legend on the cover detailing the fuses and relays. Engine Compartment (SAM Chassis): Location: On the driver's side front firewall.
Appearance: Often a black or red box located near the steering rod or washer reservoir. Power Distribution Module (PDM):
Location: Some 2019 models have a PDM located under the hood on the passenger side firewall. This box often contains high-amp fuses (like 125A) that protect the SAM modules themselves. The "No Fuse" Logic (sSAM System)
2020 Freightliner Cascadia Trailer Marker Light Fuse Location
2019 Freightliner Cascadia (New Gen model), trailer light issues are often controlled by the SAM (Signal Acquisition and Actuation Module) system rather than traditional fuses. Unlike older models that had a dedicated black fuse box on the driver-side firewall, the 2019 model typically uses Field Effect Transistors (FETs) that electronically shut off and reset once a short is cleared. Primary Locations to Check
If you are still looking for physical fuses or relays, check these three main areas:
Behind the Glove Box (SAM Cab): This is the most common location for interior and some trailer-related logic. You can access it by opening the glove box and removing the screws (typically T25 Torx).
Engine Compartment (SAM Chassis): Located on the passenger side firewall. Look for a red box; this module supplies power to the SAM Cab and Chassis.
Center Dash Floor (Lower Panel): Some auxiliary fuses are located behind the lower center dash panel, near the floor or cup holders. Troubleshooting Tips for Trailer Lights Here you will find: Step 1: Pop the
The "FET Reset": If a circuit shorts, the SAM module stops sending power. Try cycling the ignition (key off, then back on) after unplugging the trailer to see if the circuit resets itself.
Trailer ABS Fuse: While most lights are computer-controlled, there is often a dedicated physical fuse for Trailer ABS. Check for fuses labeled F25, F26, or F43 in the passenger-side panel.
Software Updates: Because the lights are computer-managed, persistent issues without a blown fuse may require a dealer to relearn the SAM values using diagnostic software like DiagnosticLink.
Pigtail/Cord Inspection: Many trailer light failures on this model are caused by faulty pigtail cords or corroded pins at the 7-way plug rather than internal truck issues. Freightliner Cascadia Trailer Light Fuse Location - Q&A
Here is the fuse location information for the trailer lights on a 2019 Freightliner Cascadia.
If you want, I can list likely fuse/relay label names from a typical 2019 Cascadia fuse diagram or guide you through testing specific pins on the 7-pin connector.
(Additionally suggested searches available.)
In a 2019 "New" Freightliner Cascadia , trailer light fuses and relays have largely been moved from traditional firewall locations and are now distributed across several key modules, primarily the SAM Cabin and SAM Chassis. Primary Fuse Box Locations
SAM Cabin (Inside Passenger Dash): Accessed by removing the glove box. This module handles many interior and cabin-related electrical systems, including some auxiliary trailer power.
SAM Chassis (Engine Compartment): Located on the driver-side firewall. This is the primary controller for exterior trailer lighting.
Vehicle Power Distribution Module (VPDM): A dedicated compartment for high-power fuses and relays located under the passenger seat.
Engine PDM: Situated under the hood on the passenger-side firewall, often protected by a red cover. Specific Trailer Light Fuses & Relays
Depending on the specific lighting issue, you should check these locations: Module Location Specific Identifiers Trailer Tail Lamps SAM Chassis (Engine Bay) Relay R9 and Fuse 13 Trailer Stop/Tail Trailer PDM / SAM Cabin Varies; check labeling on the lid Trailer Turn Signals SAM Chassis Relays R3 (Left) and R4 (Right) Trailer Auxiliary Power SAM Cabin (Dash) Fuses 61A and 61B Trailer ABS Passenger Side Fuse Box Fuses F43, F25, and F26 Freightliner Cascadia Trailer Light Fuse Location - Q&A
Guide: Locating the Trailer Light Fuses on a 2019 Freightliner Cascadia
If your trailer lights (running lights, brake lights, or turn signals) have stopped working on your 2019 Freightliner Cascadia, the issue is often a blown fuse or a tripped Breaker. Unlike older trucks where fuses were scattered, the Cascadia centralizes most fuses in the dash.
Here is a step-by-step guide to finding and identifying the correct fuses.
For the 2019 Freightliner Cascadia, open the PDM and locate the following fuse positions (note: PDM layouts vary slightly by VIN and build date—refer to your lid diagram):
