Question:
A few years back, I installed the Curt C55503 4-pin trailer wiring harness on my 2011 Kia Sedona. It worked fine for a number of years, but for the last year or so, I have noticed that it keeps all three light wires yellow, green and brown hot all the time, even when the ignition is switched off. I havent paid much attention to it, since I rarely pull a trailer and when I do, it is only a couple miles down the road, but we just purchased a pop-up with trailer brakes 7-pin connector and it appears that the brake controller/7-pin harness that I will need to install utilize the existing 4-pin harness. Is there a way to troubleshoot the 4-pin harness, or do I assume there is a problem with the harness and purchase a new one?
asked by: Craig W
Expert Reply:
What you described sounds like a shorted out converter box. Nearly every time one of the boxes fails the symptoms you described are what happens. Also, the Curt harnesses are notorious for shorting out easier than the Tekonsha. I would recommend you go with the part # 118410 after seeing if you can find the short that's on your trailer's wiring.
Now if your trailer does not have brakes all you would need is the part # 37185 as an adapter to convert the 4-way to a 7-way.
If you do have trailer brakes you would need the # ETBC7 instead of the # 37185 and a brake controller. This kit comes with everything needed to wire up the 7-way and install a brake controller.
For a brake controller I would recommend the Prodigy P2 Brake Controller part # 90885. This is our best selling brake controller because of how well it works and how easy it is to setup.
T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
Adapter 4-Pole to 7-Pole and 4-Pole
Tekonsha Prodigy P2 Trailer Brake Controller - 1 to 4 Axles - Proportional
Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires
Upgraded Heavy Duty ModuLite Circuit Protected Vehicle Wiring Harness with 4 Pole Trailer Connector