7-Way Not Working Only When Plugged Into 2017 Kia Sorento

Question:

Hello, I own a 2017 Kia Sorento which came with a 4 wire prong plug in so I had a professional install an after market 7/4 prong plug in and break controller so I could tow our pop up shortly after purchasing in 2017. I tried hooking up my camper after not using it last year and the camper lights will not work. I plugged my camper into another vehicle and the lights do work when plugged into another vehicle. I was able to test the plug in and it says the only working section on the kias plug in is the electronic breaks. I have looked into the plug on the Kia and nothing looks to be blocking any of the prongs. Any suggestions?

asked by: Brittany B

Expert Reply:

I do have suggestions, and since you have already done a lot of the legwork here I think we can find the issue. Since you plugged your camper into another vehicle and it was working fine, and your 2017 Kia Sorento's test only came back as the electric brakes working, there are a couple of possible solutions.

Though you said nothing looks to be blocking any of the prongs, I recommend first just starting off by taking as close a look at the blades as possible for any type of corrosion, which could be green or white and pretty deep in the connector. A build-up of corrosion can interfere with the signals getting through the connectors so if it is present and you can't clean it off, you are going to need to replace the plug with # C57672.

Corrosion of some type would make the most sense if you haven't used the camper in some time, so that would easily be the most likely scenario. Apart from that you will need to do some real digging, using a circuit tester like # PTW2979 to test wiring going into your harness from your tail lights to see if those wires are carrying the correct signals, if they are not then the issue is with the vehicle wiring.

That can be very tricky to find but would be something like a broken or frayed wire, so if you can somehow trace it and fit it that would be great, otherwise you would have to take it in to have it looked at and repaired. Another thing to make sure of is that your grounds are attached to bare metal surfaces and free of any paint, dirt or corrosion, which can cause interference with the signals.

Additionally, I highly recommend, in order to stave off any corrosion or damage to your trailer's electrical connections, using Dielectric Grease for Electrical Connectors # 11755.

This is going to protect your 7-way from damage and allow it to last much longer. I have added links to help articles below which I recommend checking out, and a link to a video review of the Dielectric Grease # 11755.