mocattle

I have a trailer with a 4-way hookup as well as electric brakes. My '03 F150 has both a 4-way and 7-way RV blade connector so I'm trying to hookup the 7-way to utilize the brakes. The wiring on the brakes only has a black and white wire. The wiring on the 4-way has green, yellow and brown. And I supposed to disconnect wires from the 4-way to use them on the 7-way plug and if so what do I use for the purple and blue wires on the 7-way plug? I have a brake controller installed in my truck for the electric brakes. Any advice for this inexperienced DIYer is appreciated.

kd4gij

Look here.
https://www.etrailer.com/faq-wiring.aspx

mocattle

Is there a specific section that addresses my question? I have the plug diagram that shows where each wire goes and what it's for, but I'm not sure if I'm supposed to take the wires from the 4-way and use them on the 7-way or not and if so, what I should use for the blue and purple wires?

akdoggie

On the page that opens, look to the second chart (7 colored lines) and run your wires to the plug accordingly. You can follow the picture guide on the top to be sure you have it correct.

It is sounding like you need to run the wires from the e/brakes to the trailer plug. You said your truck was wired for a 4 & 7 way plug. Just for S&G's, have you checked it to see if all the wires are there in the 7 way plug? Some have a 7 way plug as well as 4 way, but the 7 way is just the 4 way set into the 7 way plug design. Just asking, so that you don't run wires for the trailer, and not have the wiring on the truck side. Just thinking ahead.

addabob

Be careful when you interpret the wiring chart that shows the 4,5,6 & 7 way together. That is the trailer side only. It does not always align to the connector colors. I have a trailer with a 4-way and decoded to shift it over to a 7 way so I wouldn't have to use the 7-to-4 adapter Ford provided ('21s only seem to have the 7-way now as the 21-pin Pro Trailer connector is where the 4-way use to be).

The TowReady/Reese 7-way trailer end connector I got (P/N 118021) had a different mapping of the colors marked on its terminals to the wire colors to the trailer.

This pic is the back of the 7-way trailer-end plug I bought show the terminal names and functions:




This pic is the mapping I used of the original 4-way to this plug based on the TowReady values:



I was told to connect the trailer wires to the corresponding terminal color, but that is not correct. I was glad I looked at the mapping first and didn't follow that advise. This all worked like a champ and all light functions operate properly.

pegasus525

I have a 97 F-150 that came factory wired to bumper area for a 4 pin white is ground, brown is parking lights, yellow is left, green is right. Up next to spare tire there is a plug that it plugs into with extra wire's coming from the cab. The blue wire is electronic brake controller,i others are acc power and reverse. Up inside the dash next to radio on driver's side is factory wiring harness for electronic brake controller