Troubleshooting Trailer Wiring on 2010 Kia Soul that Won't Activate Tailights but Truck 4-Way Does

Question:

I purchase and installed your hitch for a 2010 Soul. I also purchased the wiring for the 4 pin Curt. I finally had an opportunity to hook up my Hallmark trailer. It is about 6 ft long and about 5 ft wide small. The lights did not work. To test out the trailer, I hooked up to my F350 pickup 7 pin with an adapter to bring it use with a 4 pin connector. The lights on the trailer work as they are suppose to. When I hoop up a 4 pin tester with LED on the connector, it appears to work correctly with the turn signal, lights, and brake lights. However when I connect my Soul to the Hallmark trailer, it does not function. No turn signal, no brake lights, nothing. The lights on the Hallmark are not LED lights. I am concerned that the Curt T-harness bought from Etrailer is either defective or not the right setup for my 2010 Soul. Do I need the unit that hooks up directly to the battery? Any assistance on this problem is appreciated.

asked by: Leonard M

Expert Reply:

One of two things are happening. Either the trailer is drawing too much amperage for the trailer wiring harness or there is a weak ground on the lights of the trailer which is causing the lights to not operate unless a more powerful wiring harness is attached.

Check the grounds for the trailer to make sure they are attached a clean metal surface. Also check condition of main ground of trailer.

Instead of going to the powered harness you could swap the lights on the trailer to LED and that would fix the problem if it's an overdraw situation. I attached a link to all of the trailer LED lights we offer.

expert reply by: Jameson C