Bed topper wiring

[Stephen Abbene]

Tomorrow I am getting a topper installed on my 2019 XLT Ranger. The topper has a 3rd brake light and interior dome lighting.

I am planning on wiring the dome lights to the 12v bed power connector. But what is the best way to wire the 3rd brake light? I thought I read a thread here that said there was a green wire behind the drivers side kick panel that I could tap into but I cannot find it anymore. I’d really rather not use vampire taps, or cut into the wiring for the rear brake lights. Any suggestions?

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[Deleted member 1634]

Are you installing it yourself? Because this isn't a new problem. Every topper comes with a third brake light and most come with interior lights nowadays. So obviously anytime a topper dealer installs it they have to wire it in, and I doubt their just splicing into existing wiring. Seems like there would be instructions and a fairly simple, almost plug and play, type of connection.

 

[Stephen Abbene]

Are you installing it yourself? Because this isn't a new problem. Every topper comes with a third brake light and most come with interior lights nowadays. So obviously anytime a topper dealer installs it they have to wire it in, and I doubt their just splicing into existing wiring. Seems like there would be instructions and a fairly simple, almost plug and play, type of connection.

Yes, I am installing it myself.

 

[Deleted member 1634]

Yes, I am installing it myself.

I guess I would hope that there's install instructions then, or at least that it's very obvious what to do, cause you're right I certainly wouldn't know what to do otherwise. Hopefully someone chimes in who has a topper and can go out and inspect theirs to give you an idea.

 

[RVA Overland]

I had a leer installed yesterday. They used a connector on the back side if the 7pin connector to get the 3rd brake light. They ran a dedicated wire to the battery for the dome light.

 

[Deleted member 1634]

I had a leer installed yesterday. They used a connector on the back side if the 7pin connector to get the 3rd brake light. They ran a dedicated wire to the battery for the dome light.

Did that mess with the trailer connect/disconnect stuff (i.e. does the truck think there is a trailer connected since it's plugged into the trailer harness wiring)? Does the 3rd brake light flash with turn signals like I've seen some other toppers on the road doing?

 

[RVA Overland]

Did that mess with the trailer connect/disconnect stuff (i.e. does the truck think there is a trailer connected since it's plugged into the trailer harness wiring)? Does the 3rd brake light flash with turn signals like I've seen some other toppers on the road doing?

Nope, truck doesn't seem to notice. I have not checked the rear brake light but it should not flash as long as they connect to the correct line.

 

[ch47dmechanic]

When the dealer installed my topper, they didn't touch my factory third brake light. The shell's brake light is wired into the trailer harness and no, it doesn't screw with the trailer settings at all. The dome light was ran all the way direct to the battery.

 

[Deleted member 1634]

Nope, truck doesn't seem to notice. I have not checked the rear brake light but it should not flash as long as they connect to the correct line.

When the dealer installed my topper, they didn't touch my factory third brake light. The shell's brake light is wired into the trailer harness and no, it doesn't screw with the trailer settings at all. The dome light was ran all the way direct to the battery.

Thanks guys! I was worried because I thought I had read on here somewhere that they did it this way and screwed things up. But good to hear that it doesn't. The topper guys said it's a lot easier and cheaper for them to just plug into the trailer wiring than splice into things, so that ended up saving me a chunk of change. Glad to hear it'll work out correctly.

 

[BcP28]

Thanks guys! I was worried because I thought I had read on here somewhere that they did it this way and screwed things up. But good to hear that it doesn't. The topper guys said it's a lot easier and cheaper for them to just plug into the trailer wiring than splice into things, so that ended up saving me a chunk of change. Glad to hear it'll work out correctly.

Anyone have pics/instructions on how they did this? Is there an aftermarket adapter for the 4 or 7pin harnesses? Did they just splice into the brake/turn signal lights?

Just wondering if this is the easier solution for the 3rd brake light. The Ford Body Builder's guide shows tapping into the CHMSL circuit on the BCM fuse panel that is located in the driver's-side foot well. The fuse panel is reachable, but sounds like a PIA to run a wire through the cab all the way to the tailgate. I ran wiring for my LED lights on the front recently, and although doable, I don't want to dig into another project like that again for awhile if I don't have to.

Here's where Ford recommends tapping (you can find the complete document here: https://fordbbas.com/publications)

 

[BcP28]

Anyone have pics/instructions on how they did this? Is there an aftermarket adapter for the 4 or 7pin harnesses? Did they just splice into the brake/turn signal lights?

Just wondering if this is the easier solution for the 3rd brake light. The Ford Body Builder's guide shows tapping into the CHMSL circuit on the BCM fuse panel that is located in the driver's-side foot well. The fuse panel is reachable, but sounds like a PIA to run a wire through the cab all the way to the tailgate. I ran wiring for my LED lights on the front recently, and although doable, I don't want to dig into another project like that again for awhile if I don't have to.

Here's where Ford recommends tapping (you can find the complete document here: https://fordbbas.com/publications)

Answered my own question. Was able to tap into the rear tail light harness to get a clean 3rd brake light signal.

https://www.ranger5g.com/forum/threads/third-brake-light-for-softopper.6784/

 

[Deleted member 1634]

Nope, truck doesn't seem to notice. I have not checked the rear brake light but it should not flash as long as they connect to the correct line.

As an update to this, I'll say that the third brake light on my new topper does in fact flash with the turn signals... quite disappointing. I've had so many issues with my topper dealer and the overall quality of the product that now I have to debate whether I care enough about this to deal with them again. I was really hoping that once I got my topper installed I wouldn't have to deal with them anymore.

 

[RVA Overland]

As an update to this, I'll say that the third brake light on my new topper does in fact flash with the turn signals... quite disappointing. I've had so many issues with my topper dealer and the overall quality of the product that now I have to debate whether I care enough about this to deal with them again. I was really hoping that once I got my topper installed I wouldn't have to deal with them anymore.

that sucks, is it when you hit the brakes and the turn signal or just the turn signal? I just went out and checked mine with the wife and that is not happening. Did they just tap into a line or did they use the wiring kit that taps into your trailers wiring harness? May be an easy fix without dealing with them again.

 

[Deleted member 1634]

that sucks, is it when you hit the brakes and the turn signal or just the turn signal?

I haven't tried applying the brake and the turn signal at the same time. Hard to do that by myself. haha I'd imagine it does though. But it does definitely flash when either or both turn signals are flashing.

I think it has to do with the wires they used. Since they tapped into the trailer harness, that means there's one wire for each side tail light that activates both brake and turn illumination. So the harness, and thereby the topper, doesn't know if it's illuminating because of braking or turning, it just knows it needs to illuminate. Which is exactly what I was afraid of.

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