[Check Trailer Lights] │ ▼ [Are Dash Fuses OK?] ──► NO ──► [Replace Passenger Dash Fuses F2, F3, or F4] │ YES ▼ [Are Chassis Fuses OK?] ──► NO ──► [Replace Exterior Chassis PDM Fuses] │ YES ▼ [Inspect 7-Way Cord & Plug Ground] 5. How to Safely Replace the Fuse
The most common location for the trailer light fuses is the SAM Chassis. This module contains the electronic controls, fuses, and relays for most of the truck's chassis electrical system, including the trailer lights.
Open the hood. Stand on the driver’s side facing the engine. Look against the firewall (the metal wall separating the engine from the cab). You will see a large black plastic box with a lid held on by two clips or screws. 2019 freightliner cascadia trailer light fuse location
The SAM Chassis controls most of the power distribution for the rear of the truck and the trailer components. How to Find the SAM Chassis Move to the exterior passenger side of the truck. Look behind the side skirt/fairing, just behind the cab.
Often labeled "TRLR MARKER" or "TRLR PARK." Trailer Stop Lights: Labeled "TRLR STOP" or "TRLR BRAKE." [Check Trailer Lights] │ ▼ [Are Dash Fuses OK
So, what do you do if this happens? It's simple. Often, all it takes to restore power to the trailer lights is to turn the truck off, disconnect the battery for a minute or two to force a full system reset, and then turn the truck back on. This restores the circuit without you having to replace a single fuse.
When your truck's lights work but your trailer lights stay dark, a blown fuse is the most likely culprit. Open the hood
The system may detect a short and cut power automatically, requiring the fuse to be reset or replaced.