Possible to connect power for camper shell 3rd brake light to truck's 3rd brake light?

I'm seriously considering getting a Tacoma for my next vehicle. I have never owned a pickup before and I am trying to do as much research as possible before pulling the trigger.

I don't really have a day to day need for an open bed so I think I will most likely get either a camper shell or tonneau cover. I am reluctant however to splice into the trucks factory cabling in order to use a camper shell.

All of the installation instructions for camper shells tell you to disconnect the trucks built in third brake light in order to stop it from reflecting on the camper shell. Then those same instructions usually tell you to splice the power for the camper's third tail light into one of the trucks brake lights.

My question is if you are already disconnecting the trucks third brake light why don't the camper shells provide a plate with a waterproof pass through and a matching wire connector to connect the power directly to the trucks 3rd brake light thus negating the need to splice into the trucks factory wiring? It seems like this would make wiring soo much easier as well as allow you to easily return the truck to factory default at any time by simply reinstalling the factory brake light. Also it would allow you to use the trucks default bed light switch to turn on the camper shell's dome light.

 

Because it would make the wiring needlessly complicated and more expensive. It's cheaper and easier just to have a plug tapped off one of the rear lights that's already closer to the third brake light on the shell. For it to be anything approaching a clean install the manufacturer would have to put the wire in the fiberglass somehow or under the carpet liner. They'd also have to provide a specific plate w/ connector for each type of truck's third brake light plus a waterproof connector at the shell. You'd need the connector to be long enough to allow the truck to flex but short enough not to flop around in the wind and scratch the paint. With the wire tap tucked up under the bed and the wires in the shell they're pretty much out of the weather too. Basically- KISS principle.

 

Ok I guess that makes sense but I'm sure it is possible to design something. I might have to look into it.

 

Sure, it wouldn't be hard to do yourself. Just make a plate to replace your third brake light lens out of something like Kydex (unless you don't mind drilling a hole in your lens), add a waterproof plug so you can disconnect the wiring then have either a waterproof pass-through or a blob of sealant on the wire as it enters the shell. From there just run the wire back to the wires for the third brake light on the shell however you choose. The plugs that come with the shells have a fuse in-line so I'd add one of those just in case.

 

Professional cap installers/dealers use a pre-made pigtail that plugs directly in to your factory wiring for the drivers side, rear brake light housing. There's no splicing and they don't touch the 3rd brake light.

If you get glare from it you can remove the 3rd brake light bulb without altering the lens. Personally I haven't noticed any glare problems with my current cap on my Taco so my 3rd brake light bulbs are still plugged in.

Running power from the truck cargo light to the canopy dome light is an option. I did that on my last truck using a bulb adaptor in the cargo light. I drilled through the cargo lens and then my canopy. I ran a pair of 16 gauge wires I sealed both holes with Geocel Proflex sealant. I never got any leaks but I wasn't happy with the appearance. If had to do it again I'd access the truck cargo light wiring the long way; through the truck cab floor, to the lick panel by the driver. There are how-to instructions on TW. The look is much cleaner than splicing and drilling through the lens. .

BTW, The canopy dome light in my new cap was hard wired to the truck battery and I like that arrangment better. The truck cargo light has a battery saver auto-off feature, like all the lights in our trucks. Not that good if you're relying on that dome light when the truck is off.