By using this guide, you can confidently locate the , diagnose the root cause, and get back on the road legally and safely.
Inspect the coiled trailer cord from the truck to the trailer. Look for chafed insulation where it rubs against the fifth wheel plate or the landing gear. A bare wire touching the frame will blow a fuse the second you activate that circuit. 2019 freightliner cascadia trailer light fuse location
If the ABS light on the dash is staying on or the trailer ABS is not powering up: By using this guide, you can confidently locate
| Function | Fuse Location | Fuse Label | Amp & Type | Typical Symptoms if Blown | | :--- | :--- | :--- | :--- | :--- | | | 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 | A bare wire touching the frame will blow
| Fuse Label / Function | Typical Fuse Amp | Slot Location | |----------------------|------------------|----------------| | (Trailer Marker Lights) | 10A or 15A | Varies – often in the middle row | | TRL L TURN (Left Turn / Stop) | 15A | Near top or right side | | TRL R TURN (Right Turn / Stop) | 15A | Adjacent to left turn fuse | | TRL BACK-UP (Reverse lights) | 10A | Bottom row | | TRL ABS (Trailer ABS power) | 10A or 15A | Separate mini-relay area |