Tekonsha T-One Connector with Circuit Protected ModuLite HD Module

Towing your boat starts with one connection your tow vehicle has to make to the trailer, and that's exactly the job this Tekonsha T-One kit handles. It's a plug-in wiring harness that taps into your vehicle's factory towing connector with no cutting and no splicing. The heart of it is the Circuit Protected ModuLite HD module, which takes your vehicle's separate turn and stop signals and converts them into the combined signal a flat trailer connector needs.

Here's why we like the T-One design. Most trailer wiring headaches start with splicing into a vehicle's wiring loom, which invites corrosion, voltage drops, and blown fuses down the road. This kit skips all of that. You find the factory harness connector under the vehicle, unplug it, insert the T-One in between, and plug the factory connector back in. The module hangs off that junction and gives you a clean 4-way flat trailer plug at the bumper. Most folks get it done in under an hour with basic hand tools. You're not chasing wiring diagrams or crimping connectors in the dark.

The ModuLite HD module is the part that earns its keep. It's a powered converter, so instead of pulling trailer lighting current through your vehicle's delicate signal wires, it draws from a dedicated power feed and switches the trailer lights itself. That keeps your vehicle's factory bulb-out warnings and body computer happy. And it's circuit protected. If your trailer wiring shorts or a bulb draws too much, the module protects the vehicle side instead of popping a factory fuse you'd have to hunt down. It handles up to 4.2 amps on the stop and turn circuit and up to 7.5 amps on the tail light circuit, which covers a standard single or tandem-axle boat trailer.

One thing to know up front. This is a vehicle-specific T-One, part number 118651. Tekonsha builds these to match a particular vehicle's factory connector, so before you order, confirm 118651 is the right fit for your year, make, and model. The plug has to match the connector under your vehicle for the no-splice install to work the way it should. If you're not sure, send us your tow vehicle details and we'll check it for you.

So who's this for? Anyone towing a boat, utility, or small cargo trailer that uses a 4-way flat connector and wants a reliable, factory-looking hookup. It's not a brake controller, and it won't run electric trailer brakes on its own, so if your trailer has surge or electric brakes, plan for that part separately. But for wiring your trailer's running lights, brake lights, and turn signals to your tow vehicle the right way, this is the clean path. It also plays nice with both incandescent and LED trailer lights, since the powered module does the switching. A lot of boaters tow the same rig for a decade, and getting the light hookup right from the start saves you the roadside troubleshooting nobody wants on the way to the ramp.

There's also something to be said for how factory this looks when you're done. Because the T-One plugs into the existing harness and the flat connector tucks up near the hitch, you don't end up with a bundle of taped wires hanging under the bumper. It's the kind of install that looks like the vehicle came from the dealer ready to tow. And when you sell the vehicle later, the wiring unplugs just as cleanly as it went in, leaving the factory harness untouched.

The whole assembly is weatherproof and built as a solid one-piece unit, which matters when it lives under a vehicle catching road spray and salt every trip. We tell every customer the same thing. Hit the connector with a little dielectric grease at the plug points, keep the flat connector capped when it's not in use, and this'll give you years of trouble-free towing. It's a small part that quietly does an important job every single time you back the boat down the ramp.