How is Power and Ground Ran to A Trailer Light with a Single Wire

Updated 01/27/2025 | Published 01/24/2025

Question:

I am running a number of clearance lights for a theatrical production. I have one-wire mounts. Do I run this one wire to the positive or negative terminal on my decoders, and how do these function without a complete circuit?

asked by: B H

Expert Reply:

Hey B, so any time clearance lights use a single wire for install that wire is the power wire and the light itself grounds through the mounting hardware. If the mounting location is not a suitable ground you can run a ground wire to the mounting hardware and that will complete the circuit. Does that make sense?

expert reply by: Jameson C

B H.

1/24/2025

I'm sorry but no. Do I run the single wire to the positive or negative terminal of my power supply? And what do I do for a return? I'm mounting to a wood surface. I understand that doesn't ground. You're saying that the ground that I need to add myself also acts as the return? If so, do I need to run it to the opposite terminal of my supply, or to any grounding surface?

Jameson C.

1/27/2025

@BH The single wire runs to the positive terminal of the battery. If you are mounting to wood you'd need to run a ground wire up to the mounting hardware of the light. Just wrap it around the screw that is getting drilled into the wood. You can run the wire for this back to the negative terminal of the battery or a solid chassis/frame ground that is metal.