Tekonsha 118427 4-Way Flat Trailer Wiring Harness
Tekonsha 118427 4-Way Flat Trailer Wiring Harness — Product description
The Tekonsha 118427 is a plug-in 4-way flat wiring harness that replaces your vehicle's OEM towing connector. It's a T-connector, so you tap the factory wiring without cutting or splicing, then you've got a standard 4-way flat for your boat or utility trailer. Clean, quick, and no guesswork on which wire does what.
The Tekonsha 118427 is a 4-way flat replacement wiring harness that plugs into your vehicle's factory towing connector. It's a T-connector design, which is the clean way to add trailer wiring. No cutting into the OEM harness, no splicing, no crimp taps dangling under the bumper. You plug it in and you're wired for a standard 4-way flat trailer connector.
If you tow a boat, this is the connector you're probably running. Most single-axle boat trailers use a 4-way flat: left turn and brake, right turn and brake, taillights, and a ground. That's the four wires. It handles everything a trailer without electric brakes needs, which covers most of the boats we see come through the ramp. If your rig is a jon boat, an aluminum fishing boat, or a small center console on a single-axle trailer, odds are it's a 4-way flat back there.
The whole point of a T-connector is that it works with your vehicle's wiring instead of against it. Tekonsha built this as a direct replacement for the OEM harness, so the plug matches what your tow vehicle already has. That means you're not chasing a wiring diagram or testing circuits with a multimeter to figure out which wire does what. It taps the factory connector and gives you a standard 4-way flat on the trailer side. Plug in, test your lights, and you're done.
Tekonsha builds towing electrical for a living, and these connectors are made to live under the bumper. The housing handles road spray, weather, and the general abuse a towing plug takes. Give it a rinse when you rinse the rest of your rig down and it'll hold up season after season.
One honest note before you order: trailer harnesses are vehicle-specific. The 118427 fits a particular set of vehicles, so check the part number against your make, model, and year before you buy. If you're not sure, send us your details and we'll confirm the fit. And if your trailer has electric brakes, a 4-way flat won't carry the brake circuit, so you'll want a different connector for that setup.
Key Features
- 4-way flat connector, the standard fit for boat trailers and utility trailers without electric brakes
- T-connector design plugs into the factory towing harness, no cutting or splicing
- Direct replacement for the OEM wiring harness, matched to the vehicle's existing connector
- Four circuits: left turn and brake, right turn and brake, taillights, and ground
- Weather-resistant connector housing built for under-bumper exposure
- Genuine Tekonsha part, number 118427
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 | 4-Way Flat Replacement For OEM Wiring Harness |
|---|---|
| Brand | Tekonsha |
| Manufacturer Part Number | 118427 |
| UPC | 016118061345 |
| Connector Type | 4-Way Flat |
| Harness Style | T-Connector (plug-in) |
| Number of Poles | 4 |
| Application | Replacement for OEM trailer wiring harness |
Frequently asked questions
What does a 4-way flat connector control?
Four circuits: left turn and brake, right turn and brake, your taillights, and a ground. It's everything a trailer without electric brakes needs to be street legal.
Do I have to splice into my wiring to install it?
No. This is a T-connector, so it plugs into your vehicle's factory towing harness. No cutting, no crimp taps, no guessing which wire is which.
Will it fit my vehicle?
Trailer harnesses are vehicle-specific. The 118427 fits a particular set of makes, models, and years, so check the part number against your vehicle before ordering. Send us your details and we'll confirm the fit.
Does this work with electric trailer brakes?
No. A 4-way flat doesn't carry a brake circuit. If your trailer has electric brakes you'll need a connector with more poles and a brake controller.
Can I use it on a boat trailer?
Yes. Most single-axle boat trailers run a 4-way flat, so this is a common fit for jon boats, aluminum fishing boats, and small center consoles.
Is this a genuine Tekonsha part?
Yes, it's the genuine Tekonsha 118427, backed by the full manufacturer warranty.
