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How to Wire a Leer Truck Cap

by Russell Wood

Installing a Leer truck cap on your vehicle adds security to the items stored in the bed as well as a distinct look that accents the body of the vehicle. Although they're easy to install and bolt onto your truck, the wiring process isn't always as straightforward, and making sure the third brake light is operating correctly is not only a legal issue, but an aesthetic one as well.

Step 1

Pop the hatch on the shell and locate the wiring for the third brake light. It typically runs through a rubber seal around the edge of the shell and then down to the bottom, where it's accessible.

Step 2

Crawl underneath the vehicle and locate the wiring that runs to your taillights. Have your assistant hold the brake pedal while you probe each light with the 12-volt test light. If the light goes on, then you've found a positive wire for the lights. Just to be sure, have your assistant repeatedly push on and release the pedal. If your light flashes in accordance with the assistant's pedal work, then you've found the right wire.

Step 3

Run the red wire from the shell through the bed and to the brake wire in the wiring harness. Place the blue scotchlok connector on the brake wire and the red wire, then clamp it down with a pair of pliers.

Find a black wire in the wiring harness and repeat the process in Step 3 with the black wire from the shell. Then have your assistant step on the brake pedal. If the third brake light illuminates, then you've done the job correctly.

Items you will need

  • 12-volt test light
  • Assistant
  • Blue scotchlok connectors
  • Pliers

About the Author

Russell Wood is a writer and photographer who attended Arizona State University. He has been building custom cars and trucks since 1994, including several cover vehicles. In 2000 Wood started a career as a writer, and since then he has dedicated his business to writing and photographing cars and trucks, as well as helping people learn more about how vehicles work.

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