Custom Towing Wiring
Custom towing wiring harnesses built for a specific year, make and model: Tekonsha T-One 4-way flat harnesses with the ModuLite HD power module, 7-way tow harnesses, fifth wheel and gooseneck 7-way bed harnesses and ModuLite trailer light power modules, with a smaller group of Hopkins Multi-tow harnesses for older trucks. Each plugs into the factory taillight or tow-package connectors and ends in a trailer plug, with no wires cut.
Listings run from the 2022-2025 Kia EV6, 2022-2024 Hyundai Ioniq 5 and 2022 Lexus NX to the 2019-2023 Ford Ranger and 2020-2025 Toyota Grand Highlander, with the fifth wheel harness covering 1997-2026 Chevrolet, Dodge and Ford trucks. Absolute Autoguard ships from Winnipeg across Canada.
Vehicle-specific trailer wiring harnesses: T-One 4-flat, 7-way and fifth wheel
Almost every harness here is a Tekonsha part. The T-One is the core: a plug-in harness that connects at the factory taillight connectors and provides a 4-way flat trailer plug, with the ModuLite HD module drawing trailer light power from the battery through its own fuse. That module is why the listings include vehicles with LED and multiplexed lighting, such as the 2022-2025 Kia EV6, 2022-2024 Hyundai Ioniq 5, 2022-2026 Mazda CX-5 and CX-50 and 2022 Lexus NX, where a passive harness would overload the lighting circuit.
The 7-way side covers trucks and larger SUVs: 7-way tow harnesses for the 2019-2023 Ford Ranger and 2020-2025 Toyota Highlander and Grand Highlander, a fifth wheel harness for 1997-2026 Chevrolet, Dodge and Ford pickups, and a fifth wheel and gooseneck adapter harness that plugs into a factory 7-way.
Shop custom towing wiring by type
T-One 4-way flat harnesses with ModuLite HD
The car, crossover and EV harness: plugs at the taillights, a battery lead with an inline fuse, and a 4-flat that tucks behind the bumper. Listed by exact year range, so the 2022-2024 and 2025-2026 Ioniq 5 are different part numbers.
7-way tow harnesses
For trailers with electric brakes. The 7-way adds the brake output, reverse lights and 12 volt charge line to the four light circuits; a brake controller from Tekonsha drives the brake circuit.
Fifth wheel and gooseneck bed harnesses
Runs a second 7-way socket into the truck bed so a fifth wheel or gooseneck trailer plugs in beside the hitch. The plug-in adapter version uses the factory 7-way at the bumper; the full harness is for trucks without one. Pairs with the gooseneck heads in Draw-Tite and B&W.
ModuLite HD power modules
The four-terminal powered converter sold on its own, for adding a 4-flat to a vehicle without a listed T-One harness or replacing a failed module. It isolates the trailer from the vehicle's lighting circuits.
Hopkins Multi-tow and older-truck harnesses
Hopkins harnesses for the 1988-2004 Toyota Pickup and Tacoma, 2003-2013 Tundra and 2000-2017 Dodge trucks, including the Multi-tow 7:4.
Shop by vehicle
- Toyota Highlander and Grand Highlander
- Ford Ranger and Bronco
- Kia EV6 and Rio, Hyundai Ioniq 5
- Honda and Acura ADX
- Chevrolet Trax and Silverado, GMC
- Mazda CX-5, CX-50 and CX-90
- Lexus NX
- Nissan, Buick, Volkswagen, Jeep, Subaru and BMW
Why buy custom towing wiring here
- Current-model coverage. Harnesses are listed for 2025-2026 vehicles, including EVs and plug-in hybrids like the EV6, Ioniq 5 and CX-90 PHEV.
- Powered modules included. The T-One harnesses ship with the ModuLite HD, so there is no separate converter to source.
- Bed wiring for gooseneck and fifth wheel. Full harness and factory 7-way adapter versions for trucks from 1997 through 2026.
- Older trucks not forgotten. Hopkins fills in the 1988-2013 Toyota and 2000-2017 Dodge applications.
Choosing the right towing wiring harness
Identify what the trailer needs first: a 4-flat if it has lights only, a 7-way if it has electric brakes or a charge line. Then look at the vehicle. If the product page lists a T-One for your exact year range, that is the part; do not stretch a harness across a model change, because the taillight connectors differ. If the vehicle has a factory 7-way at the bumper and you are adding a gooseneck or fifth wheel, the plug-in bed adapter is the simpler install. If you are not sure what fits, contact us with your year, make, model and configuration.
Common questions
What is a T-One connector?
A Tekonsha vehicle-specific trailer wiring harness that plugs into the factory taillight connectors and provides a 4-way flat trailer plug, with no splicing.
Why does my harness need a ModuLite module?
Because many vehicles with LED taillights or a body control module cannot supply the current a trailer's bulbs draw and can throw fault codes if you tap the circuits. The ModuLite reads the vehicle's light signals but powers the trailer from the battery through a fuse.
Is a 4-flat or a 7-way harness right for my vehicle?
A 4-flat covers running, brake and turn lights, which is all a utility or boat trailer needs. A 7-way is for trailers with electric brakes and campers that need a 12 volt charge line. Cars and crossovers are almost always 4-flat; trucks with a tow package are usually 7-way.
Are there trailer wiring harnesses for electric vehicles and hybrids?
Yes. The collection lists T-One harnesses for the Kia EV6, Hyundai Ioniq 5 and Mazda CX-90 mild hybrid and PHEV, each with the ModuLite HD module. The vehicle's tow rating still applies and is often limited to a bike rack.