How to Install 7-way Trailer Connector on Trailer

Question

Question:

I have a Toyota Tundra with a 7 way connector. The trailer I have uses the 4 way. I have the adapter to connect to the Tundra. No issue there. I want to add electric brakes to the trailer, but I cannot find any instructions on wiring. I need to convert the existing wiring to a seven way. Is there a converter/connector that lets you plug in the four way and then the brake wiring is a separate set of wires coming out of the connector?

asked by: Emmett T

0

Expert Reply:

If you are wanting to add brakes to your trailer, the correct way to to it would be to remove the 4-pole connector and install a 7-way harness/plug like part # H20046. You would use a junction box like part # 38656, and some 10 gauge wire like part # 10-1-1 to run the brake output circuit from the junction box to the brake assemblies. Each brake magnet will have two wires exiting it. One wire will ground to the trailer frame, the other will attach to the brake output circuit. The junction box provides a neat and weather-protected way of joining the trailer connector to the trailer wiring.

The wires from the existing 4-pole would connect to the appropriate terminals in the junction box, and the wires from the # H20046 would connect using the same terminals. Be sure to look at the table I provided, as the wire color code for the H20046 wiring won't match up color for color with the typical trailer wiring code.

I have linked you to some excellent videos showing how the junction box and wiring harness is installed.

expert reply by: Mike L

0

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Answer 1

Yes, the battery maintainer you have requires a 12 volt power source coming straight from the battery and the center pin of your 6-way is exactly that so it would work very well for you.

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Answer 2

First of all did this problem just start happening? If the trailer has always worked fine before on the same truck then it's likely a short on the trailer's brake wiring. I would start by cleaning the connector and make sure it's free of…

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Answer 3

On a trailer 7-way the pin in the 1:00 position is the 12 volt accessory circuit. You'll need to make sure that pin is active on the truck side of the wiring. But there's no way to carry that charge circuit on just a 4-way so you'll have…

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Answer 4

Those are the wires for the brake magnets. You will need to connect the black wire to the brake controller output wire on your trailer connector and you are correct the white wire will need to be grounded to a clean metal surface on the trailer. I…

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Answer 5

If you are experiencing power at the 1 o'clock position on your 7-way, the issue most likely lies with the trailer's wiring. With this situation, it is important that the trailer wiring is correctly inserted into trailer's side 7-way plug…

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Answer 6

Replacing vehicle- or trailer-side wiring is not difficult as long as you get the correct replacement part. It is often easiest to do this kind of job when you have a circuit tester like #PTW2993 to help you confirm what each vehicle wire does, and…

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Answer 7

The wiring for the Tekonsha breakaway kit #50-85-313 and trailer wiring junction box #38656 is listed below. You can also view the picture to the right. The breakaway kit will have 3 wires to hook up where as the breakaway switch will have 2 wires.…

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Answer 8

The Hopkins 7-Way RV Style Connector with Molded Cable part #H20046 is an excellent option for a trailer side molded 7-way cable and is flexible. In regards to use in the winter, this won't be a problem though the cord would be stiffer. In order…

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Answer 9

You can route the grounds from your brakes to your junction box like part #38656 but most people just ground the brakes to the trailer frame. The frame is a ground which is why this can be done, just make sure that it is a secure connection to a…

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Answer 10

If the 7-way you are referring to is the trailer side connector you will only need the blue wire in the 7-way if your trailer has electric trailer brakes. I do know that there are several trailers on the road with 7-way connectors for the charge line…

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Answer 11

If you take a look at the photos I've attached you can see how the wires from a 7-way connector can be run to junction box #38656. You would also need ring terminals #44-5310A. I've added a link to a video review, as well as an install of…

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Answer 12

For a 3500 lb Electric Jack, I recommend the Bulldog Powered-Drive Trailer Jack - Drop Leg - A-Frame - 14" Lift - 3,500 lbs - Black #BD500187. This jack uses a 12 volt system, so it is compatible with your 7-way although a battery is always a…

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How to Install 7-way Trailer Connector on Trailer

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