Trailer Wiring & Electrical – Installation Guide | Hitch Info

Chapter6 - Wiring/Electrical

Before you can legally tow your trailer on public roads, you have to have working trailer lights. In fact, this is more important than simply risking a ticket - if your trailer lights don't work, you're inviting an accident. Always check your trailer lights before you leave on any towing trip, no matter how short.

Most trailers come with lights and wiring installed for you. If your trailer's lights and wiring are missing or beyond repair, it's usually very easy to install replacements. Any reputable camping or trailer center will have kits that use standard wiring connections and standard color-coded wires.

Understanding Trailer WiringTrailer wiring harnesses use 4 to 7 wires to control basic lighting and brake functions. The simplest connectors for the smallest trailers use four wires on a flat plug to control tail lights, brake lights, and turn signals. Connectors with 5, 6, and 7 wires add (in order) backup lights, electric brake control, and auxiliary power. To make trailer wiring less confusing, there's a standard color-coding for each of the 7 possible wires and their functions. The chart in Figure 6-1 shows standard wire colors and their functions:

4-Way

5-Way

6-Way

7-Way

Green

Yellow

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Trailer Wiring & Electrical - Installation Guide | Hitch Info