Wiring a Third Brake Light for a Camper Shell on a 2009 Nissan Frontier  

Expert Reply:

In order to wire up a third brake light on a camper shell you are going to need to locate a dedicate brake light only circuit on your 2009 Nissan Frontier. The tow package wiring will not work because the turn signals and brake light circuits are on the same wire.

You could use the third brake light at the top of the cap (if equipped) and tap into the brake light there by removing the light to access its wiring.

Or you could use a fuse tap and tap the CHMSL fuse. Use the owners manual to find the CHMSL fuse location.

And finally, a place that installs camper shells may know of a wire under the truck that carriers a brake light only signal.