Will A Non-Powered Trailer Wire Harness Converter Still Allow Factory Light Signals Through
Updated 02/03/2026 | Published 07/02/2024
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Question:
Will the original vehicle taillights work without powering the converter module? Longer context: My car is 2021 Mazda CX-30. I am considering doing the installation by myself, but I dont like the idea of routing the power cable underneath the vehicle to the battery as done in the installation video. Instead, I plan to plug the power cable into the 12v socket. When not towing, I will not supply power to the converter module. So the question is, will the original vehicle taillights still work if the converter module is not powered? Thank you!
asked by: Kai
Expert Reply:
Hey Kai,
Plug-in wire harnesses like the Curt # C86CR would still allow the vehicle light signals through to the tail lights regardless if the converter was powered or not. I don't recommend connecting the power line to a separate 12v socket and turning the power on and off since it wasn't intended to be used in this way and could potentially cause issues/wear out the converter faster.
Running the power line up to the battery is super easy to do it and if you're really worried about protecting the wire you could also shield it with some wire loom # 7509-10.
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
- Converter
- No Tow Package
- 4 Flat
- Plug and Lead
- Plug-In
- Hidden
- CURT
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on Custom Fit Vehicle Wiring
Robin H.
2/3/2026
Hey Kai, how did things go with the Curt wiring harness on your CX-30? Did running the power line to the battery and using the wire loom make the setup easier? Your update could make it easier for others planning a similar wiring job.