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Discussion Starter · #1 ·
I have an extra tailgate light bar laying around and was thinking it would be perfect to use in my bed for lighting. I would like to connect the reverse lights of the bar to the cargo lights in the 3rd brake light assembly - so whenever I engage the cargo light switch in the cab, the light bar (reverse lights only) in my bed illuminate with the cargo lights in the 3rd brake light.

Can someone tell me where I would find and how I would access the wire for the cargo lights in the 3rd brake light so I can t-tap into it?
 

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I have an extra tailgate light bar laying around and was thinking it would be perfect to use in my bed for lighting. I would like to connect the reverse lights of the bar to the cargo lights in the 3rd brake light assembly - so whenever I engage the cargo light switch in the cab, the light bar (reverse lights only) in my bed illuminate with the cargo lights in the 3rd brake light.

Can someone tell me where I would find and how I would access the wire for the cargo lights in the 3rd brake light so I can t-tap into it?
The wire is located under the door sills on the driver side, its part of the wire harness, I tapped into it just under the driver side rear passenger sill. Now you want to know what wire color, well I don't remember, but what I did was remove the 3rd brake light and looked at the color of the wires there, then went down to the door sill wire harness and found the wire, used a needle with a volt meter to find it, my wire for my bed lights comes in via the hole plug under the rear seat, so it was easy to tap in at that area. I think on my truck it was a white/light blue wire. Hope this helps.
 

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Discussion Starter · #3 · (Edited)
Yep, that makes it more clear. Thanks for that. I think I have a better idea of what to expect and where to look. So, I run the reverse wire (light bar mounted with wire end oriented toward the cab) through a hole (that I need to cut?) in the bed, under the cab, and up through a hole plug under my rear bench seats and over to the door sill where I can remove the sill guard and find a loom containing the wire from the 3rd brake light assembly? Is this right? Will I need to run the 12V hot (red) wire from the bar to a power source (I am assuming, lol)? Is there a 12V source in the loom in the door sill? It would be nice to run the reverse and 12V wires together and tap both into the same location..
 

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Yep, that makes it more clear. Thanks for that. I think I have a better idea of what to expect and where to look. So, I run the reverse wire (light bar mounted with wire end oriented toward the cab) through a hole (that I need to cut?) in the bed, under the cab, and up through a hole plug under my rear bench seats and over to the door sill where I can remove the sill guard and find a loom containing the wire from the 3rd brake light assembly? Is this right? Will I need to run the 12V hot (red) wire from the bar to a power source (I am assuming, lol)? Is there a 12V source in the loom in the door sill? It would be nice to run the reverse and 12V wires together and tap both into the same location..
Depending on where you place your light bar you can use the holes at the top front of the bed to bring your wires out, you will need the "white" wire from the light bar (+) and the black wire (-), run these 2 wires down the inside of the fender of your bed (accessed from the hole I mentioned) down and under the cab, bring the wires in via the plug, RTV silicon the wires to the plug where they pass as to keep anything from entering the cab. then connect the (black) wire to the body ground of the truck, usually you can just use a sheet metal screw on the inside of the cab under the carpet or find a body bolt and connect it to there with a wire connector, and then tap the white wire to the wire I spoke about. So now when you have tie wrapped all that up and its clean, you can press your unlock button and your bed light and your light bar will light. Very simple, this is how i set mine up. So often I need something in my bed under the tonneau at night and just press my unlock and it lights up the box. If I need it on for a long period, I press the button on the dash.
 

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How'd this go?

Thanks for the info! I'll be playing with this project this weekend..
Looking to do this same thing, using LED strip lights as the camper shell dome is pathetic.

I'm trying to A) identify the cargo light wire that is in the door sill (white with tan stripe?) and B) that the additional (less than 1 amp) draw does not cause the onboard diagnostics to shut the circuit off.

Also, I will be running a dedicated set of LED banks under the bed rails to a switch at the tailgate for additional light when loading/unloading for extended periods.

Hoping this thread isn't zombied out.

Thanks for sharing your findings!
 

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Looking to do this same thing, using LED strip lights as the camper shell dome is pathetic.

I'm trying to A) identify the cargo light wire that is in the door sill (white with tan stripe?) and B) that the additional (less than 1 amp) draw does not cause the onboard diagnostics to shut the circuit off.

Also, I will be running a dedicated set of LED banks under the bed rails to a switch at the tailgate for additional light when loading/unloading for extended periods.

Hoping this thread isn't zombied out.

Thanks for sharing your findings!
Have been running a set of bed lights linked to the cargo lights now for over a year with no issues, cargo lights + 8 LED units with each 8LED's in the and no issues. Hope that helps
 

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Have been running a set of bed lights linked to the cargo lights now for over a year with no issues, cargo lights + 8 LED units with each 8LED's in the and no issues. Hope that helps
Any chance I could get you to take a peek at where you tied into the cargo lamp circuit?

Many thanks.
 

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I tied my bed lights into the domes, my full mod thread can be found here.
 

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i ran some wires up the front bed post on the drivers side, (it was a different project), there was a round hole in mine & it was near the top of the bed.
I ran the wiring along the door sill, like you mentioned, then i ran it under the carpeting & into the little compartment that is located under the drivers side rear passenger seat, there was a drain hole located there



this is an image of the bed on the passenger side, look at the stake post at the front, you can see the hole in the stake post near the top.



The project that i did was 2 separate power supply sources, they supply power to the Auxiliary 30 gallon Gas Tank Fuel Pump & my Orange Rotating Lights



The switches are mounted in the cubby hole in my dash

 

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Any chance I could get you to take a peek at where you tied into the cargo lamp circuit?

Many thanks.
I grounded the negative wire to the body ground and ran a wire up under the rear driver side seat and up into under the sill area, there i just tapped into the wire that goes to the cargo lights at the top back of the cab. I don't remember the color of the wire, but if you pull the 3rd brake lite off you can see what color the cargo wires are. then just find it under the sill and tap into it, I like this setup cause if I just need a quick light I can press the unlock on my FOB and they light up, if I need ti for a long time to be on, I can press the cargo light button on the dash and thats it. Hope this helps
 
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