trailer light issue

motorboatinking · 03-21-2015, 06:11 PM

I drive a 2013 Outback, and have a 1996 Jayco Eagle 8. My car only has a 4 way trailer harness, and the trailer has a 7 way plug. The owner before me only had a 4 way vehicle, so he added a 4 way plug to the trailer, and literately zip tied brake lights to the rear of the trailer. I want to use the trailers lights, so I bought an adapter, but I am having issues. The front lights on the trailer work correctly, but all the lights on the rear of the trailer do not. I took a bulb out and swapped it with the front, and the rear still did not work, and the front did, so it's not the bulbs. I am getting about 5 volts to the brake lights when the vehicle brakes are hit. I'm not sure if that is enough or not. How do I go about trouble shooting from here?

Also, the trailer does not have brakes, and I am not concerned with a 12v hot wire, unless that is the issue, so the three wires coming off the adapter are just there. I did ground the adapter and it has continuity to the negative terminal car battery. Also, the trailer has a battery and it is hooked up.

**norty1** · 03-21-2015, 06:16 PM

Welcome, Sure makes you sick to have to fix someones mess.

I can't help you from here but hopefully someone will chime in.

ninjahbob · 03-21-2015, 07:49 PM

http://www.triplecrowntrailers.com/a...ug-diagram.pdf

Try the above sight and see it can help with your wiring problem.

NVGun40 · 03-21-2015, 08:21 PM

Your trailer has a 7 way plug because of the onboard battery. Part of your trailers wiring harness from the plug goes to the converter to provide a charge to the trailers battery while under tow. However, the trailers exterior road light system should will still be a common system. Perhaps the previous owner tapped in and changed this around a little bit when they put the 4 way system on it.
My recommendation is to start at ground level with the trailers harness to ensure the 7 way is still wired properly. It may sound difficult, but it really isn't. Next, I also recommend setting your tow vehicle up for the 7 way connector. The non utilized aspects of the 7 way will not harm your TV and you will have the piece of mind knowing it is set up properly. It is far easier to adapt a 7 way down to a 4 way than to go from 4 way up. In fact there are pre-made plug and play adapters out there to go from 7 to 4. Worse case scenario, you can re wire the trailers lights underneath.

NVGun40 · 03-21-2015, 08:24 PM

BTW, where in Alaska are you?

motorboatinking · 03-21-2015, 08:26 PM

I followed the harness up the trailer a little and the 7 way gets stepped down to a 6 way square harness. I'm not sure if that is common, and if the wiring is messed up between the 6 way and the 7 way. I also had a friend with a properly wired 7 way on his truck come over and hook up. The brakes worked, and the left turn signal, but nothing else did. So I think I'm going to return my 4-7 way adapter and pick up a 4-6 square and see if eliminating the 7way helps at all

motorboatinking · 03-21-2015, 08:27 PM

Quote:

Originally Posted by NVGun40

BTW, where in Alaska are you?

Outside of Fairbanks

motorboatinking · 03-21-2015, 08:32 PM

What is in my hand is the 7 way, about 4 feet of wire, then a 6 way. And the trailers 6 way is on the frame below

NVGun40 · 03-21-2015, 08:53 PM

So the 6 way appears to be the factory harness on the trailer?
If it is what I am thinking, the 6 way allows for the trailer light wiring system plus the 12 volt charging line. Again, I recommend coming off the vehicle with the set up. Just ensure the 12 volt lead for charging should be connected to a 12 volt lead off the vehicle on a switched conductor. This way the 12 volt power running to the trailer from the vehicle is only on when the vehicle ignition key is on. Make sure you check all the light bulbs for functioning. On older systems grounding connections can be corroded.

I am in Eagle River down outside of Anchorage.

exjay1 · 03-21-2015, 08:58 PM

I'd start from scratch just from the fact there is alot of "hacking mods" done to the existing wiring. Wire and mount up a 7 way correctly to your TV and have worry free travels.

motorboatinking · 03-21-2015, 09:03 PM

Ok. Makes me a little nervous, but makes sense. How generic are wiring kits? Can I just buy one and it will work, or do I need to try and go through Jayco and get a specific harness?

MadDad · 03-21-2015, 10:22 PM

The three most important things to look for when you have trailer light problems are:
1- check the grounds
2- check the grounds
3- check the grounds

NVGun40 · 03-22-2015, 09:27 AM

There is an industry standard to wiring kits. Since you are just out of Fairbanks, head over to Six Robblees. They will have the harnesses you need. Its all pretty straight forward. As well, they should be able to supply with a simple to read and understand wiring diagram.
In some cases, there are quick plug and play adapters for putting a receptacle on a vehicle so there may be no need for wire splicing (I know there are kits for most pickups, unplug the vehicle wiring harness at a specific point where there is a plug in connector. Plug in the trailer receiver wiring hardness, mount the plug and you are off and running).

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