Because trailer wiring is prone to shorts from water or road debris, manufacturers often separate the trailer circuits from the vehicle’s main lighting. This guide will help you track down exactly where those fuses are hidden. Start With the Owners Manual
Before you start slicing wires or cursing the trailer manufacturer,
Trailer lighting is often split into multiple fuses rather than just one. If your running lights work but your turn signals don't, you are likely looking for a specific fuse. Common abbreviations include: Trailer Brakes TRLR RT: Right Turn/Brake Light TRLR LT: Left Turn/Brake Light TRLR PK: Trailer Parking/Running Lights TRLR AUX: 12V Auxiliary Power to the trailer How to Identify a Blown Fuse trailer lights fuse location
| Component | Typical Location | Notes | |-----------|------------------|-------| | | Under dashboard, driver’s side (left-hand drive vehicles) | Most common location for trailer lighting fuses, especially for turn/brake signals. | | Secondary fuse box (engine bay) | Near battery or in a black plastic box under hood | Often contains fuses for tail/running lights and the trailer lighting relay. | | Trailer tow module fuse | Engine bay or rear cargo area (near spare tire) | On vehicles with factory towing packages; sometimes a large fuse (20–40A). |
The 7-way plug that connects your trailer to your tow vehicle can also have a fuse, especially if it's a newer setup. This fuse might protect the wiring for the trailer lights. Because trailer wiring is prone to shorts from
1️⃣ This is the most common spot for the "Tow Package" fuses. Look for a black plastic box near the battery. Pop the cover and look for fuses labeled:
If your trailer has its own wiring system with a fuse or circuit breaker, it might be located: If your running lights work but your turn
Fuses for trailer lights are typically labeled using one of the following terms:
A wire on the trailer frame has rubbed raw and is touching metal. The ground wire is loose or disconnected.
