Is 12V Power Connection Required for Tekonsha T-One 4-Pole Wiring Harness 118718 to Function

Question:

I plan on using this to power a few LEDs and currently run LEDs in all of the bulbs on my 2019 CX-3. I understand its powered so as not to overload the factory wiringinch but given that information it should have more than enough capacity to run two more LED bulbs. Is it necessary to run power to this unit, or will it run fine un-powered?

asked by: Dan S

Expert Reply:

Yes, the Tekonsha T-One 4-Pole Wiring Harness # 118718 will work fine to power LED lights on a trailer or accessory carrier used with your 2019 Mazda CX-3 but it does require the 12V power wire connection in order to function.

The plug-in connectors will take in the car's lighting signals which essentially serve as switches to tell the converter to send lighting power out to the 4-pole. The actual current to operate the lights comes from the power wire that you route up to the battery; the vehicle wiring just serves to tell the converter what to do. A powered harness like this is the best way to protect your vehicle's internal wiring from risk of damage from a short or overload.

You can refer to the linked article for help with the routing of that power wire. Please note that an accessory 12V power outlet (now often found in the rear of vehicles) is not suitable for powering the harness since it is current-limited. The direct battery connection is required.

expert reply by: Adam R