ATM Wiring Harness Installation Instructions
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The new U-Haul Advanced Trailer Module (ATM) wiring harness is the most innovative aftermarket trailer wiring yet.
Most aftermarket trailer wiring used today is ‘dumb’ – that is, it simply takes a signal from the vehicle and routes it to the trailer lights. However, new vehicles feature more sensors and electronics than ever before, such as back-up safety sensors that automatically stop the vehicle when something (or someone) is behind it.
If a trailer is hooked up to one of these vehicles, then that backup safety sensor will prevent the vehicle from moving. Until now, wiring that disables these sensors when a trailer is in tow has only been available as an add-on from the vehicle manufacturer.
The new U-Haul Advanced Trailer Module wiring harness solves this problem. It’s a ‘smart’ wiring system that mirrors the original equipment manufacturer’s functionality by piggybacking off the factory connection. It doesn’t require any cutting or splicing, making it easier to install than standard wiring, and it’s entirely compatible with some of the most popular vehicles in the US and Canada.
It also costs significantly less than wiring packages at your local dealership – while you may pay upwards of $650 USD for parts and labor at the dealership, you’ll only spend $200 USD at U-Haul for an equivalent product. U-Haul is the first (and only) 3rd-party trailer hitch installer to offer this unique wiring harness.
If you’re interested in this trailer wiring, simply fill out our digital hitch finder form with your vehicle’s year, make, and model, then select the “OEM Style” wiring type under “Wiring” if available for your vehicle. You can also purchase the wiring directly from our online store, though you should check that it’s compatible with your vehicle first.
If you own the U-Haul ATM wiring harness already, then follow the installation instructions below that correspond to your vehicle:
Vehicles Using ATM4001A
Hyundai Santa Fe (2024-2026)
The ATM4001A harness is designed to integrate with the factory tow-ready circuits on the 2024–2026 Hyundai Santa Fe. This system communicates directly with vehicle safety sensors to allow proper towing functionality.
Installation Instructions and Video
- Download the Full PDF Instructions: Coming soon
Vehicles Using ATM4002A
Hyundai Santa Cruz (2025)
The ATM4002A wiring harness provides OEM-style trailer wiring for the 2025 Hyundai Santa Cruz. The harness connects to factory points behind interior trim panels and includes a dedicated fuse and module mounting location.
Installation Instructions
Download the Full PDF Instructions: HyundaiSantaCruz2025.pdf
Kit Components
- ATM control module
- Vehicle-specific A/B connectors
- 20-Amp mini fuse
- Mounting bracket
- Zip ties and hardware
Hyundai Santa Cruz Installation Steps
- Access the trim panel: Remove the driver-side rear trim panel to expose the factory wiring block (PDF p. 4).
- Connect A and B harness plugs: Plug the ATM connectors into the OEM connectors as shown (PDF p. 8).
- Route the trailer socket lead: Route the harness toward the hitch following the diagram on page 3 (PDF p. 3).
- Install and mount the 7-way socket: Secure the socket bracket and connect the X-lead (PDF p. 6).
- Insert the 20-Amp mini fuse: Install the fuse in the location shown (PDF p. 8).
- Reinstall trim and reconnect the battery.
- Perform the functional test: The trailer lights must draw at least 1W of power for proper detection (PDF p. 9).
Vehicles Using ATM4003A
More Vehicles Coming Soon!
Future Vehicle Coverage
Additional ATM wiring harness instructions will be added as more vehicles become compatible.
Safety Warning
Improper installation of trailer wiring may cause electrical shock, vehicle damage, or fire. Always disconnect the battery before installation. Installation should be completed by a qualified professional.
How Much Does It Cost to Add a Hitch?
A trailer hitch generally ranges from $195–$215, plus another $100-$200 in labor costs for installation depending on hitch class and receiver size. U-Haul offers both 1¼" and 2" hitches and provides professional installation at any U-Haul Moving Center®, or you can choose home delivery for DIY installation.
How Much Does Hitch Installation Cost?
Hitch installation typically costs $100–$200, depending on:
- Hitch class and model
- Local U-Haul labor rates
- Vehicle design and underbody layout
Every trailer hitch installed at a U-Haul Moving Center® is eligible for a lifetime hitch warranty, which covers collision damage, corrosion, accidental overload, jackknifing, and even vehicle theft. Wiring protection plans are also available.
How Long Does Installation Take?
Installation for either vehicle usually takes 1 to 2.5 hours, depending on the hitch style and the underbody features of the vehicle. U-Haul service centers also offer towing accessories (ball mount, hitch ball, pin and clip, wiring kits) to complete your setup during the same appointment.
Do You Need a Wiring Kit to Tow?
Yes! Any trailer equipped with lights requires a wiring harness to power running lights, brake lights, and turn signals. U-Haul offers:
- 4-way connectors for basic lighting
- 7-way connectors for reverse lights, trailer brakes, and 12V power
- OEM-style ATM wiring harnesses for vehicles with advanced electrical and safety systems
Both the 2024–2026 Hyundai Santa Fe and the 2025 Hyundai Santa Cruz may require an Advanced Trailer Module (ATM) harness to properly integrate with modern safety sensors and onboard electronics.
Use the Hitch Finder on uhaul.com to confirm the correct wiring configuration for your vehicle.
Where Can I Get My Hitch Installed?
With more than 1,500 U-Haul Moving Centers® nationwide, you can schedule an installation appointment online and get your hitch installed quickly and professionally. Most customers are in and out the same day.
Find your trailer hitch and wiring kit today at uhaul.com.