Why Should I Run the Trailer Power Wire Directly to My Battery Instead of a Vehicle Power Source?
Updated 09/02/2025 | Published 08/15/2025
Question:
Why wire directly to the battery and not a vehicle on power source?
asked by: Earl M
Expert Reply:
Hey Earl!
The thought process behind running the Curt T-Connector # C29ZV wiring harness power wire up to the battery is so that your trailer lights won't be drawing power off of any circuits on your 2025 Hyundai Santa Fe. It offers an extra level of protection both for the circuits on your vehicle, and to ensure that your trailer lights won't go out due to too much power being drawn from any given circuit in your vehicle.
We've had a handful of people ask this question in the past and while I definitely see the reasoning behind it, when it comes to towing, I'm all about the safety side of things and that's ultimately what it boils down to; getting to your campsite/vacation/outing safely.
I've installed similar kits on a few vehicles here in our shops at etrailer as well as one at home on my 2010 Town and Country. It was definitely easier running the wire on a lift, but it also wasn't too bad on my van either. I installed my hitch and the wiring at the same time so I just backed my van up on the ramps I use for changing oil and it gave me more than enough room to mess with the wiring at the back and run it up to the front.
What do you plan on using the wiring kit for? Towing, or another accessory (like a bike rack)?
(click to enlarge)
Product Page this Question was Asked From
Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
- Custom Fit Vehicle Wiring
- Trailer Hitch Wiring
- Vehicle End Connector
- Powered Converter
- No Tow Package
- 4 Flat
- Plug and Lead
- Plug-In
- Hidden
- CURT
more information >
Featured Help Information
Instructions
Continue Researching
- Search Results: 7 pole adapter
- Shop: Trailer Hitch
- Shop: Trailer Wiring
- Video: Installing the Curt T-Connector Vehicle Wiring Harness on a 2025 Kia Telluride
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Shop: Brake Controller
- Shop: Vehicle Tow Bar Wiring
- Shop: Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
- Search Results: wireless brake controller
- Shop: etrailer Trailer Hitch Receiver - Custom Fit - Matte Black Finish - Class III - 2"
- Shop: 7-Way RV Upgrade Kit for Trailer Brake Controller Installation - 12 Gauge Wires
- Video: Mount: 7-Way RV Upgrade Kit for Trailer Brake Controller Installation on a 2023 Kia Telluride
- Search Results: redarc trailer brake controller
- Shop: T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
- Shop: Tekonsha OEM Replacement Vehicle Wiring Harness w Brake Controller Adapter - 7 Way Trailer Connector
- Video: etrailer Class III Trailer Hitch Step-By-Step Installation - 2025 Kia Telluride
- Video: Install: 7-Way RV Upgrade Kit for Trailer Brake Controller Installation on a 2020 Kia Telluride
- Shop: BTBRV Magnetic Hitch Receiver Reducer Sleeve - 2-1/2" to 2" - Red
- Video: Curt TriFlex NEXT Trailer Brake Controller DIY Installation - 2025 Kia Telluride
- Q&A: What Stealth Hitch Fits The 2025 Kit Telluride X Pro Prestige And Can It Be Used With WD Hitch
- Video: Redarc Tow-Pro Liberty Brake Controller Installation - 2023 Kia Telluride RED24FR
- Shop: Curt T-Connector Vehicle Wiring Harness for Factory Tow Package - 7-Way Trailer Connector
- Article: Brake Controller Installation: Starting from Scratch
- Article: Routing the Power Wire for a Trailer Wiring Harness
- Article: Wiring Trailer Lights with a 7-Way Plug (It's Easier Than You Think)
- Q&A: Can the 12 Volt Power Wire from a Trailer Wiring Harness Tap Into a 12 Volt Accessory Outlet
- Q&A: Connecting Relay To 7-Way Charge Line Circuit To Prevent Trailer Draining Vehicle Battery While Off
- Q&A: Why Does Trailer Wiring Kit Have to Run Wire to Battery Directly
- Video: Redarc Tow-Pro Liberty Brake Controller Review RED24FR
- Q&A: Installation Instructions for Tekonsha Voyager Brake Controller
on Custom Fit Vehicle Wiring
Jon G.
9/2/2025
Hey Earl, How did the installation of the wiring kit go for you? I'm curious to know if you found it straightforward or if you ran into any challenges, as your experience could be helpful for others considering similar setups.