Is Diode Required to Wire Roadmaster RM-155 Flat Tow Lighting Kit to License Plate Light

Question:

Kit rm-155 Kit does not cover instructions for the rear license plate light. Do i need a diode if i tap into the license plate light?

asked by: Mitch R

Expert Reply:

The Roadmaster Tail Light Wiring Kit # RM-155 is an independent flat towing lighting system that includes bulbs, sockets and the wiring and connectors to install them in your F-150's taillight assemblies. This allows this flat towing wiring system to remain completely separate from the truck's own internal wiring.

If you want to wire in your license plate light so that it too illuminates then you WILL need to use diode # RM-690 to prevent the installed bulbs from illuminating when you're driving the vehicle on it's own. The diode will prevent the license plate light from activating the bulbs in the RM-155 kit.

expert reply by: Adam R