Does anyone know if the 2017 super duty has a wire available to connect a 3rd brake light for a topper?

 

If your wiring it yourself there are wires in the hitch you can tap, they are capped off. Ill post a picture from my phone.

 

Wow you were handy

good job

 

I think if you tap into the trailer wiring the truck will sense a trailer being hooked up at all times. I found in older f150's there was a designated wire for it. Cant find anything on the new superdutys .

 

But thinking this morning hooking the brake light from the topper will not work, it will cause it to flash when you use your turn signal for that side. As far as making the truck think a trailer is there I dont think LED's have enough resistance to do that, I believe it need to detect brake resistance. I will be able to test this a soon as I run that red wire to the battery.

 

A topper manufacturer told my cap dealer that there is a purple with white stripe wire by the hood release haven't found it yet.

 

You'd be surprised. I re-did my old man's car dolly with LED fixtures, 4 of them total, and the truck would actually dimly flash those lights when turned off as it checked for a trailer, but it still recognized it. I think it would catch even a single LED fixture.

If you're OK with that, you could make or buy some kind of AND gate which would make the light work as a brake light unless the hazards are on. I am idly hunting for a CHMSL wire, but if I don't find one, I'll do something similar, as I want to separate the brake lights from the turn signals on my flatbed.

https://www.etrailer.com/Accessories...rt/C56196.html < something like that.

 

I found a two wire connector on the frame behind the drivers seat for the interior of the cap light. Need to ask dealer if there is a harness for it. Never did find the third brake light wire.

 

This thread is about how a topper was installed using the brake light wire from the trailer plug, using an adapter on the back of the trailer electrical connector plug.

https://www.ford-trucks.com/forums/1...installed.html

 

Every one of my previous Super Dutys had the wires at the back of the vehicle. It is taped to the trailer harness. All you do it cut it free and your in business.
And I've had a topper with a 3rd brake light on all of them.

 

I found a brake control wire on the passenger side kick pnl with the pto wires. Violet wire cbp04 is the tag. I got the extra bed light wire from a connector buy the passenger doors mounted on the outside of the frame. I tried a 1/4 w led at the trailer plug for the brake but the truck saw it as a trailer connected.