I purchased a tonneau cover to go on my 2020 F150. It has a brake light/turn signal along the tailgate side. It has an adapter that plugs in between the wiring harness and the factory installed trailer plugs. Since this taps into the trailer lights, the computer senses the power draw and thinks there is a trailer attached. This takes away the guide lines when the truck is in reverse as well as the auto-stop/start.

Is there a way to disable the trailer detection? As of right now, I don't plan on pulling any trailers, but I can't say I never will. To note: all I did was plug the harness in. I didn't do any type of setup to the "trailer" in the system. I bought this truck used.

 

Clip the brake/turn wires to the cover so it only has parking/marker lights. The truck will still have brake/turns.

 

That's a pretty bold move. Hopefully I can find a way to test this theory prior to snipping wires. That is an option if it works. Thanks!

 

Option #2 (of probably a dozen or more): unplug the tonneau. The trucks' lights will still work.
Option #3: buy a jumper harness to put between the truck & tonneau connectors, and cut (or don't connect) the jumper's brake/turn wires.
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Have the installer move it over to the truck circuit.

 

The "installer" is me and I don't know how to move it over to the truck circuit. I'm sure I could eventually figure it out, but I'd more than likely just unplug the cover rather than spend my time trying to figure all that out.

 

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Option #4: splice the tonneau's brake/turn wires into the truck's brake/turn wires, instead of plugging them into the truck's trailer connector.
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Start by taking your taillights out.

Couple screws and yank them out carefully (not carelessly) so you dont break a tab. Takes less than a minute.

Send an email to the cover manufacturer and ask them “where do you suggest I use scotch connectors to hook this up?”. Its pretty well protected in there so use those just hang them in a way so water can run down them, like female end down if that makes sense but probably doesn’t matter. But really you should shoot an email or call tech support of the bed cover manufacturer.


The only issue you will have is LED vs Halogen if you use the truck circuit. Are both the same type of light?

 

In the GARBAGE, exclusively. NEVER use them on a vehicle, or anything else you want to work reliably.