Roof Rack Light Bar Wire Routing Discussion

Hey everyone,

Haven't seen anything here that specifically mentions routing wires from under the hood to lights/accessories on a roof rack. I had some success rewiring my roof rack lights yesterday so I'll share what I learned and hopefully help someone else in a similar position.

I need to run 4 wires (2 hot, 2 ground) for my setup consisting of a 42" light bar and 270 degree down lighting. Previously I unsuccessfully tried to tuck my too-large wire bundle under the windshield gutter, so this time around I began with slimness in mind.

I started with some bonded 16ga 4-wire trailer wire from Home Depot and wrapped that in 5/8" 3:1 heat shrink for protection. Routing from under the hood, through the grommet in the windshield boot, and tucked that bonded 4-wire vertically into the crack on the OUTSIDE of the windshield gutter using a deadblow hammer and a piece of cardboard to tap it in place.

The fit is super tight and did not require any adhesive. It's nearly invisible except at the top where it pops out to go under the roof rack's fairing. I think this is a pretty solid method for routing roof rack wiring.

@CaliRaisedLed 42" light bar
@victory4x4 roof rack and 270 degree down lighting

https://www.homedepot.com/p/TowSmart-Bonded-Trailer-Wire-1432/206798846

$10 XHF 5/8" 10Ft 3:1 Waterproof Heat Shrink Tubing Roll Marine Grade Adhesive Lined Heat Shrink Tube, Insulation Sealing Oil-Proof Wear-Resistant Black

https://www.amazon.com/dp/B0919H9XQD?ref=ppx_pop_mob_ap_share

 

Good write up

This is great for those looking to run wires to the roof. When I first decided to run scene lighting it took me a while to find a place to run the wires. I ran the same rout as you but ended up using a black pvc wire sleeve. Instead of a hammer and cardboard to shove into place, I had a plastic trim removal tool that worked really nice as well.

 

Do you have pictures of how yours turned out?

I also used a trim tool to make room for the front edge of the bonded wire and then used the hammer to get it fully seated in the crevice.

 

It honestly looks identical to yours other than a different rack and light set up. Once diode dynamics releases ssc1’s I’ll be redoing everything up there. I never realized how useful side lighting can be until I had it. I don’t think I’ll ever not have it again. Still debating on if I’ll run passenger/driver to different switches though. Which if I do, I now know I can fit 4 16g wires in that little channel thanks to your post.

 

Yeah man totally agree about the side/rear lighting. I can flick those on and see everything around me on the drone strike cam - also great for loading up in the dark.

Why exactly would you want left/right switches?

 

That's a far cleaner and much less destructive method than drilling a hole in the A-pillar. For the life of me, I could never figure out why folks drilled holes so water could run down (undetected) into the truck and main fuse block. Not that it would ever cause a problem or anything ...

 

I did not know that was a thing people do. Seems unnecessarily destructive

 

Oh yea. And if you think all of them deburr the hole (and add a grommet and sealing) so they don't cut through the insulation, you'd also be wrong.

 

two reasons actually.. my awning and where I normally set everything up is on the passenger side. So I’d like to light that up without lighting the whole truck up. Second, I do a lot of night time fishing on the beach and it’s frowned upon by the park service to shine bright lights over the ocean (tricks the turtle hatchlings into thinking it’s the moon and causes them to travel towards the dune line opposed to the ocean.. or so they say). So at night I can still have my camp area and not shine towards the water.

more of a convenience really, but those are most definitely two times I’d prefer to have two switches.

 

was there a specific reason you ran 4 wires instead of combining the grounds so only 3 wires were technically needed?

 

That would be true if the 16ga wire is sufficient to handle the power coming off of both lighting circuits simultaneously. I did not do the calculations so I'm not sure. For this application is was no more difficult to use 4 wire so I kept the circuits separate.