Why the Different Color Systems for 4-Way and 7-Way Trailer Connections?

Question

Question:

Seven wire color codes vs four wire color codes. When I connected a new seven connector harness to my trailer, I matched the wires color for color. The left turn signal flashed the running lights, the headlights turned on the right turn signal and the right turn flashed the right running light. When I compared the color chart associated with my seven connector harness to a chart for a four wire harness I noticed the color codes were completely different except for white, it was ground for both. My trailer appears to be wired according to the four wire code so it should be a simple fix for me to switch a few wires. My question is why the different color systems?

asked by: David P

1

Helpful Expert Reply:

That is a really good question, and unfortunately the manufacturers don't give a direct answer. They just say matching function is what is needed and colors don't always match from any vehicle or trailer manufacturer.

I have found color coding makes a whole lot of sense with the traditional color functions being brown for running lights, yellow for left brake/turn, green for right brake/turn, white for ground. This has been the industry standard for trailer lighting on smaller trailers for decades. Then for 7-way you add the blue for brake controller, black for 12V power, and purple for reverse light on traditional color systems.

Some manufacturers follow this and others like Hopkins give a completely different color code for what seems to be no reason other than already addressed above. I've attached the chart for the Hopkins 7-Way RV Style Connector with Molded Cable - Trailer End - 8' Long - RV Standard # H20046 as an example.

If you don't have the conversion chart it gets even more fun to match functions with locations. I've attached an article to further assist.

expert reply by: Jason S

1

click to enlarge

Answer 1

Since your 2022 Toyota Highlander does not have the factory tow package the trailer wiring harness you'd want is the Tekonsha part #TK99FR which is the easiest to install and most reliable. Then for a hitch the Curt #C99FR would be a great option…

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Answer 2

The Tekonsha T-One Vehicle Wiring Harness #TK99FR does include both the converter and the 4 Flat plug and will be very similar to the OEM Toyota parts you found, just put together in one kit. I included an image that should clear everything up for…

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Answer 3

Yes. You can use your existing weight distribution hitch with the Gen-Y Torsion 2 Ball Mount #325-GH-1324 without any additional components, but it is not the optimal setup. Gen-Y recommends that you use the Gen-Y Torsion Weight Distribution Shank -…

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Answer 4

The difference between the Class II and Class III hitches has to do with their Gross Trailer Weight (GTW), their Tongue Weight (TW), and their Hitch Receiver Size. Class II trailer hitch receivers have a 1-1/4 inch receiver and can be rated up to…

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Answer 5

If you've securely connected the Tekonsha T-One Wiring #TK74FR to your 2022 Toyota Highlander but you aren't getting any power to the 4-Way then it sounds like your Highlander doesn't have the factory tow package and you needed the T-One…

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Answer 6

A 4-Way trailer connector has the basic lighting functions only; running lights, left turn signal and brake lights, right turn signal and brake lights, and ground. A 7-Way has these functions and a 12 volt circuit, a circuit for electric trailer…

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Answer 7

I attached a picture that shows what type of lighting requirements are needed for a trailer over 80 inches in width as well as a link down below that covers this as well.

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Answer 8

Yes, we do. To add a hitch to your 2024 Toyota Grand Highlander, I recommend the Curt Trailer Hitch item #C26VV. This hitch is custom fit and bolts to your Toyota with included hardware. This is a class III hitch with a 2" receiver. It has a…

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Answer 9

For some reason Toyota isn't very forthcoming with how to figure out if you have the tow package or not. From my understanding all of the V6 models of the 2019 Toyota Highlander have the tow package but it isn't specified as to what else…

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Answer 10

To add a hitch to your 2024 Toyota RAV4, I recommend the etrailer item #e23ZR. This hitch is custom fit and bolts to your Toyota with included hardware. This is a class III hitch with a 2" receiver. It has a 4,000 lbs towing capacity, and a 600…

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Answer 11

Yep, so long as your 2024 Subaru Crosstrek Wilderness is not a hybrid both the Curt and etrailer hitches will fit: - Curt Trailer Hitch Receiver #C13382 - etrailer Trailer Hitch Receiver #e98912 The only difference besides price is the finish; the…

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Answer 12

If you just need a 4-pin to 7-pin trailer wiring adapter, then you can use part #C57672. This will plug into the 4-pin trailer connector on your brother's vehicle and give him the 7-pin socket for the trailer. Keep in mind, this will only give…

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Why the Different Color Systems for 4-Way and 7-Way Trailer Connections?

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