Hey guys - I just purchased a used LEER 100XR Canopy for my Super duty. It has the TAG box in the canopy to wire up your 3rd brake light/dome light and unlock/lock function. I ordered the harness to wire the 3rd brake light and dome light. I found the factory dedicated CHMSL (brake light) by the spare tire. My question is what have you all used to connect the dome wire? I want it to be a constant 12V so I can turn the dome on when the truck is off. Wasn't sure if there was something from the factory already back there or if I need to run a wire all the way up to the battery? Below is a link to that harness. Thanks in advance!

 

Mine has constant 12v from the battery, but I also ran LED lights around the interior ceiling.

 

Nice. I am thinking about adding LEDs as well. Did you find a good path to run that wire all the way up there? Did you go straight to the + terminal on the battery?

 

I went straight to the battery with an inline fuse

 

In my Chevy I had a 7-way t-harness adapter the topper dealer used for power and 3rd brake light. Chevys leave 12v hot all the time to the 7-way, which is fed up to the tag interface. The T harness uses a converter to convert the left and right tail light signals to a chmsl signal for the topper. Very similar to the converters you’d use to get trailer lights on a car with no provisions.

After a few years, I noticed that my 3rd brake light would just turn on randomly while sitting in the driveway. I eventually just removed the chmsl wire from the converter and used the dedicated one from Chevy under the bed. I capped and sealed off the old wire from the converter and left it in place since I used the converter for the 12v. Hindsight being 20/20, I should have removed the entire converter and rewired the whole harness to just get the 12v to pass up to the topper.

Fast forward a year, maybe two… at like 4 in the morning, my truck started on fire while sitting in the driveway. It had been sitting for 12+ hours. After reviewing the footage, I can’t tell exactly what happened, but the fire started under the bed, near where the 7 way is. Maybe a pest got in there and chewed up the wires, or maybe it was that converter box… there was nothing left of the truck so the investigation didn’t go anywhere.

anyway, all of this to say… be careful with the boxes they/you use to install the stuff you’re using. Ford may not be live 24/7 like Chevy, but it could still happen. The boxes are almost all cheap Chinese junk with almost no QC. To further clarify, it wasn’t the TAG box that started the fire, that’s up in the topper. It might have been the converter on my T-Harness under the truck. Maybe. Who really knows.

 

Damn. Sorry to hear that. I have read several posts now about those adapters just causing problems. Definitely plan to avoid those. I'll keep it simple and just run straight to the battery for the 12V power w/ Inline fuse.

 

Mine is wired into the bed lights so when you turn on the bed light the dome light is on.

 

I ran a wire from the accessory harness under the hood near the passenger side battery back to the canopy harness.

 

When I ordered the Leer 100r for my 2021 I went with the battery operated interior light instead of the wired light like I had on the Leer cap in the previous 2012 truck. Always hated having the power needed to be on for the light. Now just flip the switch and replace a couple batteries when needed, much easier.