wiring for 3rd brake light in topper

[Orlip]

I just purchased a topper for my truck and I was wondering if anybody knew which wires to tap into for the 3rd brake light. Its on a 05 Ram 2500.

[john.wells]

You don't really need to tap into the brake lights at all, unless you want to. By law, you are covered with the factory lighting of the truck. I don't know off hand which wire you need, but you could tap into the trailer outlet connector for the brakes. If you have a test light, you can figure out which one it is in short order. Just be sure to use a nice watertight connector, and route the wiring so it doesn't short to ground anywhere.

[Hafnutz]

If your truck has separate brake lights and turn signal lights then all you need to do is connect to the brake light circuit.If the turn signals and brake lights are combined and use the same lamp then you need to connect to the turn signal/brake light wire on each side and use diodes to prevent a back flow of current which would cause your 3rd brake light to blink if the turn signals and brake lights are on at the same time. Most shops that sell toppers can set you up with the necessary parts.

[hitthebricks]

I have an idea for you, how about switching the red lense for a clear one and wire it to your reverse lights so you have more light when backing up at night. HTB

[Mike89]

you can also make a jumer from your trailer harness wires.