Tekonsha Tow Harness, 7 Way Complete Kit TK22125TekonshaOriginal price was $316.25. Current price is $243.88.Out of Stock
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2019 - 2021 Freightliner Sprinter 2500
Confirmed to Fit
2019 - 2021 Freightliner Sprinter 3500
Confirmed to Fit
2019 - 2024 Mercedes-Benz Sprinter 2500
Confirmed to Fit
2019 - 2024 Mercedes-Benz Sprinter 3500
Confirmed to Fit
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Tekonsha Tow Harnesses are the replacement for your factory electrical connector to the back of your vehicle. These harnesses are used to link the wiring from your vehicle to the trailer when towing. Tekonsha Tow Harnesses feature custom designs to fit each vehicle make and model based on manufacturer specifications. Plus, the Plug & Play connectors on the end of the wires make it easy to install. No cutting or splicing!
Tekonsha offers the largest, most complete line of Replacement Tow Harnesses. Hit the road with the peace of mind only Tekonsha can provide. Life's a Journey. Stop Often.
| BRAND: | TEKONSHA |
| PART NUMBER: | 22129 |
| WARRANTY: | LIMITED 1 YEAR WARRANTY |
| WEIGHT: | 4 LBS |
| UNIVERSAL OR SPECIFIC FIT: | SPECIFIC |
| CIRCUIT PROTECTED: | YES |
| HARNESS TYPE: | MALE FEMALE |
| TERMINAL QUANTITY: | 7 |
| WIRE COLORS: | BROWN, GREEN, YELLOW, WHITE |
| WIRE QUANTITY: | 7 |
| WIRE GAUGE: | 18 AWG, .85 AVSS |
| POWER LEAD REQUIRED: | YES |
| ELECTRICAL SYSTEM TYPE: | MULTIPLEXED SYSTEM |
| HARDWARE INCLUDED: | NO |
| AMPERAGE: | 30 A |
Tekonsha is a leading manufacturer of electronic trailer brake controllers, pioneering the category in the 1970s. The lineup spans proportional units such as the Prodigy P3 and Prodigy iD, time-delayed controllers, the wireless Prodigy RF, plus vehicle-specific wiring harnesses, adapters and trailer brake components engineered for smooth, predictable stopping at any speed.
Tekonsha Engineering Company began in 1964 building RV steps and mirrors. Within a few years it had found its real calling, and by the 1970s Tekonsha was pioneering the manufacture of electronic trailer brake controllers, the product category that still defines the brand. More than half a century later it remains the reference name in trailer braking and is part of the Horizon Global group alongside Reese, Draw-Tite, Fulton, Bulldog and Wesbar.
A brake controller is the component that tells a trailer's electric brakes how hard to work and when, and getting that right is the difference between a controlled stop and a shove from behind. Tekonsha builds both major types. Proportional controllers use an internal accelerometer to sense how quickly the tow vehicle is slowing and apply trailer braking to match, so light braking stays light and hard braking is immediate. Time-delayed controllers ramp to a preset output over a fixed interval, a simpler and more economical approach that suits occasional towing.
The current brake controller range covers most of that ground. The Prodigy iD pairs with a phone through Tekonsha's EDGE technology for setup and monitoring, the P3 offers storable settings for multiple trailers and a trilingual colour LED display, the Prodigy P2 adds a dimmable display and boost mode for heavier loads, and the Voyager keeps operation simple and dependable. The Prodigy RF mounts to the trailer itself and controls wirelessly, which suits rental fleets and drivers who swap tow vehicles.
Installation is supported by vehicle-specific brake control harnesses that plug into a factory connector rather than requiring cut-and-splice wiring, along with mounting brackets and adapters. Matched controller bundles pair a unit with the correct harness. Products are tested to meet and often exceed published industry standards.
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4 compatible vehicles
| Year | Make & Model | Notes |
|---|---|---|
| 2019 - 2021 | Freightliner Sprinter 2500 | Tow Harness Wiring Package Drilling Required Install Time is 120 minutes |
| 2019 - 2021 | Freightliner Sprinter 3500 | Tow Harness Wiring Package Drilling Required Install Time is 120 minutes |
| 2019 - 2024 | Mercedes-Benz Sprinter 2500 | Tow Harness Wiring Package Drilling Required Install Time is 120 minutes |
| 2019 - 2024 | Mercedes-Benz Sprinter 3500 | Tow Harness Wiring Package Drilling Required Install Time is 120 minutes |
The Tekonsha Tow Harness, 7 Way Complete Kit TK22129 (Part #TK22129) fits 2019-2021 Freightliner Sprinter 2500 models. The 2024 model year is the last year covered by this part number. For newer models, check for an updated version.
Yes, the Tekonsha Tow Harness, 7 Way Complete Kit TK22129 (Part #TK22129) is designed to fit the 2019-2021 Freightliner Sprinter 2500.
The Tekonsha Tow Harness, 7 Way Complete Kit TK22129 (Part #TK22129) fits the following vehicles: 2019-2021 Freightliner Sprinter 2500; 2019-2021 Freightliner Sprinter 3500; 2019-2024 Mercedes-Benz Sprinter 2500; 2019-2024 Mercedes-Benz Sprinter 3500. Always verify your specific year, make, and model before ordering.
The Tekonsha Tow Harness, 7 Way Complete Kit TK22129 (Part #TK22129) Drilling is required for installation. Basic hand tools are typically all you need.
The kit includes a 7-way socket and connector, T-One Connector with Modulite lighting module, brake control harness, tow harness with power module, cable ties (8.5-inch and 14.5-inch), wire taps, fuses (one 25 AMP and two 30 AMP), ring terminals (4), fuse holders (3), yellow and blue butt connectors, red 18 GA wire, grommet, double-sided tape, and hardware. Tools required include wire strippers/crimpers, wire cutters, Phillips #2 screwdriver, 8mm/10mm/15mm sockets, Torx T-25 and T-30 bits, trim panel puller, 2-inch hole saw and drill, heat gun, and a tester or volt meter.
No. The brake control harness is included, but the brake control itself is not included in this kit. The harness is designed to work with Tekonsha Brake Controls (models 90195, 90885, or 90160). Visit www.tekonsha.com for details on where to purchase a compatible brake control.
The manual does not specify vehicle makes, models, or years. The kit is designed for vehicles with rear combination lights, a CHIMSL (Center High Mount Stop Light), and battery access under the driver's side floor mat. Confirm your vehicle has these features before purchasing. Contact Tekonsha at 800-632-3290 or www.tekonsha.com for fitment verification.
Yes. The manual explicitly requires you to disconnect and isolate the vehicle's negative battery terminal before beginning installation. Reconnect the negative battery cable only after all wiring is complete and secured.
You must remove: the foam corner piece behind the driver's headrest (partially), the interior trim piece behind the driver's side door, the driver-side bumper fascia and air baffle, snap-in air vent covers on the left and right vertical columns inside the cargo area, and the trim piece along the driver-side ceiling. Some grommets may need to be altered to allow wires to pass through; seal altered grommets with silicone.
Yes. Two holes must be drilled: (1) a 2-inch hole using a hole saw at the bottom of the bumper on the driver's side, and (2) a 3/32-inch hole for the ground stud near the T-One Connector black box. For the 2-inch hole, deburr the bare metal and coat it with primer. Before drilling the 3/32-inch hole, verify what is behind the surface to avoid damage to the vehicle or personal injury. Do not drill into the vehicle floor or bed, and do not drill into exposed surfaces.
A 2-inch hole saw is required. Drill at the bottom of the bumper on the driver's side. Deburr the bare metal and coat it with primer. Be sure to avoid drilling through additional materials beyond the intended hole.
A 3/32-inch hole is drilled to secure the white ground wire using the eyelet and screw provided. This hole should be located near the T-One Connector black box at a suitable grounding point. Before drilling, verify what is behind the surface to avoid damage. Do not drill into the vehicle floor or bed.
Open the rear doors and use a Phillips screwdriver to remove the rear combination lights and set them aside. Push the vehicle connector through the gasketed hole into the rear cargo area pillar. The T-One Connector ends (with yellow wire on driver's side, green wire on passenger's side) are inserted between the vehicle and taillight connectors. Ensure all connector surfaces are clean and free of dirt before inserting.
Mount the T-One Connector black box using the double-sided tape provided. First, clean the flat mount surface area using a 50-50 mixture of rubbing alcohol and water. Press the black box firmly onto the cleaned surface. The box should be mounted near a suitable grounding point.
Use a test light to identify the +12V wire. Connect the test light to a wire and press the brake pedal. The test light will illuminate when the brake is pressed if you have found the +12V wire. Once identified, connect the 18 gauge red wire to this +12V CHIMSL wire using the wire tap provided, then connect the other end to the 18 gauge red wire of the body harness using a blue butt connector.
Beginning on the driver's side, route the body harness with jacketed red/black/blue wires toward the front of the vehicle. Route the harness behind plastic and foam trim pieces along the ceiling, then follow the existing wire route to the battery under the driver's feet. Route wires carefully to avoid hot pipes, heat shields, the fuel tank, or any other points that may pinch or break the wire.
The 7-way harness uses a 12 gauge red wire connected to the vehicle's positive battery post. This wire is protected by a 25 AMP fuse holder (labeled Tow Harness). Connect using a butt connector and ring terminal to the positive side of the battery.
The brake control harness uses a 12 gauge black wire connected to the vehicle's positive battery post. This wire is protected by a 30 AMP fuse holder (labeled Brake Control power). Connect using a yellow butt connector and ring terminal to the positive side of the battery.
The brake control harness uses a white wire for the ground connection. Route this wire to an existing vehicle chassis ground point and secure it using the provided ring terminal.
The brake control harness uses a blue wire for the electric brake output. Route this wire to the body harness blue wire and connect using a butt connector.
An 18 gauge red wire is used to connect to the CHIMSL (Center High Mount Stop Light) +12V wire. This wire is connected using a wire tap provided in the kit, then connected to the 18 gauge red wire of the body harness using a blue butt connector.
The kit includes three fuses: one 25 AMP fuse for the Tow Harness power module, and two 30 AMP fuses for the 7-way harness and brake control power. The 25 AMP fuse protects the main power module. The 30 AMP fuses protect the 7-way harness and brake control circuits.
No. The blue wire tap provided is for 16-18 gauge wire only. When splicing, use appropriate gauge wire splices for the wire size you are connecting.
When using a volt meter or circuit tester, carefully probe one wire at a time. Do not probe across two wires or across vehicle structure, as this can cause damage or incorrect readings.
Apply heat directly to the butt connectors using a hot air gun or other heat source, working from the center out to the edges, until the tubing recovers and the adhesive flows. Allow the connectors to cool completely before inspecting the splice and checking its integrity.
Secure the harness with the cable ties provided (24 pieces of 8.5-inch ties and 1 piece of 14.5-inch tie). Be careful to avoid any areas that would pinch, cut, or melt the wire. Route wires away from hot surfaces and sharp edges.
Using the wire insertion detail provided in the manual, insert the seven wires into the 7-way connector. Refer to the wiring diagram on page 1 for the correct wire colors and positions: brown (right/stop), red (left/stop), white (ground), yellow (back up), green (tail), blue (trailer brakes), and black (+12V battery).
The manual states to determine a suitable 7-way mounting location on the tow vehicle but does not specify a particular location. The 7-way socket bracket is not included in the kit. Route the 7-way harness behind the rear bumper fascia and over the bumper support bracket toward your chosen mounting location.
Determine a suitable mounting point on the tow vehicle for the electric brake control harness. The manual does not specify a particular location. Secure the brake control harness connector near the desired brake control mounting location.
Test and verify the installation with a test light or trailer once installed. Ensure all lights function correctly (tail lights, brake lights, turn signals, and backup lights). If using a test light, probe one wire at a time to verify voltage at key connection points.
Replace all coverings, grommets, and any other components that were removed for ease of installation. Some grommets will need to be altered to allow wires to pass through. Seal altered grommets with silicone to prevent water intrusion and protect the wires.
Wear safety glasses during installation. Read and follow all vehicle warnings and installation instructions before beginning. Route wires carefully to avoid hot pipes, heat shields, the fuel tank, or any other points that may pinch or break the wire. Before drilling, verify what is behind any surface to avoid damage to the vehicle or personal injury. Do not drill into the vehicle floor or bed, and do not drill into exposed surfaces.
Overloading circuits can cause fires. Do not exceed the stated product ratings. The kit includes fuses rated at 25 AMP (tow harness power module) and 30 AMP (7-way harness and brake control power) to protect against overload. Ensure fuses are properly installed and not bypassed.
The kit is designed for vehicles with rear combination lights, a CHIMSL (Center High Mount Stop Light), and battery access under the driver's side floor. The manual does not list specific vehicle makes or models. Contact Tekonsha at 800-632-3290 or www.tekonsha.com to confirm fitment for your vehicle.
Required tools include wire strippers/crimpers, wire cutters, Phillips #2 screwdriver, 8mm/10mm/15mm sockets, Torx T-25 and T-30 bits, trim panel puller, 2-inch hole saw and drill, heat gun, and a tester or volt meter. A ratchet and metal primer paint are also needed.
Yes. Disconnect and isolate the vehicle's negative battery terminal before beginning installation. Reconnect it only after all wiring is complete and secured.
The brake control harness is designed to work with Tekonsha Brake Controls models 90195, 90885, or 90160. The brake control is not included in the kit. Visit www.tekonsha.com for details on where to purchase a compatible brake control.
Test and verify the installation with a test light or trailer once installed. Ensure all lights function correctly. If the 7-way connector is not functioning properly, check that T-One Connector ends are fully inserted and locked, and verify chassis grounds are secure.
First, ensure the T-One Connector ends are fully inserted and locked in place. Remove the Tow Harness power module 25 AMP fuse for 10 seconds and repeat the test. If the problem persists, check that chassis grounds are secure—ensure ring terminals are in full contact with the vehicle's bare chassis metal. Remove the 25 AMP fuse for 10 seconds and repeat the test.
The installation may have activated circuit protection. Start the vehicle and turn all functions off: tail lights (headlights), brake, and turns. Remove the Tow Harness power module 25 AMP fuse for 10 seconds and repeat the test. If power is still absent, verify the 25 AMP fuse is fully inserted into the fuse holder with no breaks. Check that the fuse holder is connected properly to the positive post of the battery. Using a tester or volt meter, check for voltage on either side of the yellow butt connector near the module. Remove the 25 AMP fuse for 10 seconds and repeat the test.
Ensure the module is connected to B+ (positive battery). Using a tester or volt meter, check for voltage on either side of the yellow butt connector near the module. If voltage is present on one side but not the other, the connector may be faulty. Remove the Tow Harness power module 25 AMP fuse for 10 seconds and repeat the test. If problems persist, contact a Tekonsha approved installer for professional installation at http://www.tekonsha.com (enter your zip code in Where to Buy).
Sam
The staff was able to quickly assist me with locating the correct product I needed. Shipping was really fast. Item arrived in 2 days. Will be using TowUniverse again!!
May 22, 2023
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