| Function | Fuse Location | Fuse Label | Amp & Type | Typical Symptoms if Blown | | :--- | :--- | :--- | :--- | :--- | | Main Trailer Module Power | Under Hood (PDM) | F47 | 30A J-Case | No trailer lights at all | | Tail / Marker Lights | Under Hood (PDM) | F30 | 20A J-Case | No running lights or clearance lights | | Left Turn / Stop | Under Hood (PDM) | F31 | 15A Micro 2 | Left blinker inop; no left brake light | | Right Turn / Stop | Under Hood (PDM) | F32 | 15A Micro 2 | Right blinker inop; no right brake light | | Reverse Lights | Under Hood (PDM) | F33 | 10A Micro 2 | No backup lights on trailer | | 7-Way Constant Power | Battery Box | CB1 | 50A Breaker | Trailer battery not charging / ABS won’t power up | | Stop/Turn Main | Battery Box | CB2 | 20A Breaker | Brake lights work on tractor but not on trailer |
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| [Relay] [Relay] [30A] [30A] |
| [15A] [15A] [10A] [--] |
| [10A] [TRL MKR] [15A L] [15A R]| <-- Trailer lights here
| [5A] [10A] [--] [10A] |
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Note: Always verify with your vehicle’s fuse map as minor variations exist between early and late 2019 production. 2019 freightliner cascadia trailer light fuse location
In the 2019 Cascadia, the main fuse panel is located inside the cab, on the driver’s side. | Function | Fuse Location | Fuse Label
(Note: There is also a fuse box under the hood/bunk for ABS and power lines, but trailer lighting circuits are almost exclusively routed through the dash panel.) Note: Always verify with your vehicle’s fuse map
If you check fuses 60, 61, and 62 and they are all fine, but your trailer still has no lights, look for a J-Case fuse labeled Fuse #1 (usually 30 or 40 Amp).
This larger fuse powers the entire trailer lighting module. If this is blown, nothing on the trailer will work.