Tekonsha 118849 T-One Connector | 4-Way Flat
Tekonsha 118849 T-One Connector | 4-Way Flat — Product description
The Tekonsha T-One Connector is the plug-and-play way to wire your tow vehicle for a trailer. It taps into your factory harness with no cutting or splicing and gives you a clean 4-way flat connector. A built-in converter keeps the trailer lights isolated from your vehicle's electrical system.
The Tekonsha T-One Connector is about the simplest way to get a tow vehicle wired for a trailer. It's a vehicle-specific harness, so instead of cutting into your factory wiring and chasing down which wire does what, you find the connector the manufacturer already built into your truck or SUV, unplug it, and plug the T-One in between. That's the whole idea behind the T in the name.
On the trailer side you get a standard 4-way flat connector. That covers your running lights, plus left and right turn and brake, everything most single-axle trailers need. If you're towing a boat trailer, a small utility trailer, or a pop-up, a 4-way flat is almost always the connector you're looking for.
This version includes the upgraded converter module, and that's the part worth understanding. Some vehicles combine the turn and brake signals on one circuit, and some have sensitive electronics that don't love having trailer lights hung directly off them. The converter reads the vehicle's signals and drives the trailer lights on their own protected circuits. Your factory bulbs and modules stay isolated. If the trailer wiring ever shorts out, the converter takes the hit instead of a fuse buried in your dash.
Installation is genuinely plug-and-play. No splicing, no test light, no scotch-locks. Most folks have it done in the driveway with hand tools in well under an hour. The connectors are keyed, so you can't get them backwards. The trailer-side plug is molded and sealed, so it holds up to road spray and weather once it's mounted and you're not fighting corrosion a season later.
One thing to check before you order: the T-One is matched to specific vehicles by year, make, and model. This part number fits a particular set of applications, so confirm your vehicle before you buy. Not sure? Send us your year, make, and model and we'll tell you straight whether 118849 is the right harness for your rig.
Key Features
- Vehicle-specific T-One design plugs into your factory tow harness, no cutting or splicing
- 4-way flat trailer connector powers running lights plus left and right turn and brake
- Upgraded converter module isolates trailer lighting from your vehicle's electrical system
- Dedicated circuit protection guards your vehicle's wiring from a trailer short
- Keyed, plug-and-play connectors install in the driveway with basic hand tools
- Backed by Tekonsha, an established name in trailer wiring and brake control
Why Buy from NVN Marine
- Authorized Tekonsha reseller, full manufacturer warranty
- NMEA member and ABYC certified, advice from real boat techs
- Same-day shipping before 3 PM ET on in-stock items
- NY headquarters and Fort Lauderdale flagship retail store
Technical specifications
| Title | T-One Connector; Plug and Play; With 4-Way Flat |
|---|---|
| Brand | Tekonsha |
| Manufacturer Part Number | 118849 |
| UPC | 016118162219 |
| Connector Type | 4-Way Flat |
| Installation | Plug-and-Play (T-One), no splicing |
| Wiring Style | Vehicle-specific harness with converter module |
| Trailer Functions Powered | Running lights, left turn/brake, right turn/brake |
| Vehicle Fit | Vehicle-specific by year, make, and model |
Frequently asked questions
What is a T-One connector?
It's a vehicle-specific trailer wiring harness. Your vehicle already has a factory tow connector tucked behind the bumper or under the cargo area. You unplug it, plug the T-One in between, and you've got trailer wiring with no splicing. The T shape is where the name comes from.
Do I have to cut any wires to install it?
No. That's the whole point. The connectors are keyed and plug straight into your factory harness, so there's no cutting, no scotch-locks, and no test light hunting for the right wire.
What does the 4-way flat connector power?
Running or tail lights, plus left and right turn and brake. That's everything a standard single-axle trailer, boat trailer, or utility trailer needs. A 4-way flat does not carry a separate electric brake or 12V charge circuit.
What's the green wire on a 4-way flat for?
On the standard 4-way flat color code, green is the right turn and brake signal. Brown is running lights, yellow is left turn and brake, and white is ground. Match those and your trailer lights track your vehicle.
Why does this version have a converter?
Some vehicles combine turn and brake on one circuit, or run sensitive lighting electronics that don't like trailer loads wired straight in. The converter reads the vehicle's signals and drives the trailer lights on their own protected circuits, so your factory wiring stays isolated.
Will 118849 fit my vehicle?
The T-One is matched to specific vehicles by year, make, and model, so this part number only fits a particular set of applications. Send us your year, make, and model before you order and we'll confirm whether it's the right harness.
