Trailer Electrical & Lights
LED tail and marker lights, wiring harnesses, plugs and connectors, junction boxes, and breakaway kits — Curt, Hopkins, Optronics & comparable. Most lighting problems trace to a bad ground or corroded plug; parts to fix either are on the shelf.
Electrical & Lights we carry
- LED Tail Lights
- Marker Lights
- Wiring Harnesses
- Connectors & Plugs
- Breakaway Kits
- Junction Boxes
Don’t see it? We special-order too. .
Find a Part
Let’s Find the Part You Need
Your parts counter
Pick a store to see its parts line and hours. Your request goes straight to that counter.
Tell us what you need
Before you order electrical & lights
A few things to check so the part fits the first time, or just tell us what you’ve got and the parts team will spec it with you.
- Match the connector
- Flat 4, flat 5, 6-way round, or 7-way blade. The plug sets the wiring and which functions you get.
- Confirm the hole size
- LEDs drop into most housings; confirm the grommet/opening diameter (2″, 4″, oval) before ordering.
- Name the function
- Stop/turn/tail, backup, or marker, and tell us if it’s a submersible boat-trailer light.
- Breakaway is the law
- Brake-equipped trailers need a working breakaway kit and a charged battery to be legal. We stock the full kit.
Electrical & Lights in our catalog
A sample of the trailer electrical & lights in our parts catalog. Tap any part to see the details, then request it from your nearest store.
- 5th Wheel Wiring Harness Kit 10' for bedHopkins
- Battery Charger 12V for Breakaway BatteryCurt
- Brake Controller Tekonsha Primus IQTekonsha
- Brake Controller Tekonsha Prodigy P2Tekonsha
- Brake Controller Tekonsha Prodigy P3Tekonsha
- Break Away Pin Only Small Hopkins 20051Hopkins
- Dometic Ceiling Air Distribution Manual Non-DuctedDometic
- Fill Rite 18 GPM Clear Bowl Hydrosorb FilterFill-Rite
- Hydrastar Controller Adapter Module/HBA-CamHydrastar
- Plug for 3.75" ALKO Oil CapAL-KO
- Pump Fill-Rite Transfer 12V DC 15 GPM 3/4x12' HoseFill-Rite
- Pump Fill-Rite Transfer 12V DC 20 GPM 1"x12' HoseFill-Rite
This is a sample, not the full catalog. If you don’t see it, .
Electrical & Lights FAQ
- Why do my trailer lights not work?
- Check the ground first — the white wire and its connection to the frame cause most trailer light problems, especially flickering or lights that work only when the trailer is hitched. After that, look for corrosion in the plug, cut insulation along the frame, and blown fuses on the tow-vehicle side. A test light or multimeter at the connector tells you quickly whether the problem is on the truck side or the trailer side.
- What's the difference between a 4-pin and 7-pin connector?
- A 4-pin (flat) carries the basics: running lights, left and right turn/brake, and ground. A 7-pin (round RV blade) adds circuits for electric brakes, 12V auxiliary power, and reverse lights. If your trailer has electric brakes, you need a 7-pin. Adapters exist in both directions, but an adapter can't add brake control a 4-pin truck doesn't have.
- What is a breakaway kit and do I need one?
- A breakaway kit is a small battery, a switch, and a pull-pin cable attached to the tow vehicle. If the trailer ever separates while towing, the pin pulls and the battery applies the trailer's electric brakes. It's required in most states on trailers with brakes — and worth having regardless. Replace the battery if it won't hold a charge; it only works if it's charged.
Need trailer electrical & lights?
Tell us the trailer and the part. The nearest store confirms fit and availability.