What fuse in a 2003 Ford Expedition controls trailer lights?

There isn't one single fuse that controls *all* trailer lights on a 2003 Ford Expedition. The trailer lights are controlled by several fuses, and possibly a relay, depending on the specific configuration (tow package or not). To find the correct fuse(s), you need to consult your owner's manual. The manual will have a fuse box diagram showing which fuse(s) are responsible for the trailer lights' power circuits.

Look for fuses related to these possibilities:

* Trailer Tow: There may be a fuse specifically labeled "Trailer Tow" or something similar.

* Tail Lights: The trailer lights often share circuits with the vehicle's tail lights, so check fuses for the tail lights.

* Turn Signals: Similarly, trailer turn signals often share circuits with the vehicle's turn signals.

* Stop Lights: Trailer brake lights often share circuits with the vehicle's brake lights.

Without your owner's manual, I can't give you the specific fuse numbers. Always refer to your owner's manual for the most accurate information.