wiring license plate light on horse trailer

Old 07-24-18, 06:13 AM
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wiring license plate light on horse trailer

Had to replace the license plate bracket & light. The trailer has a black wire and a white wire at the site. The new bracket only has a black pigtail on it, Where does the white one go?
The mechanic insists it's a ground, and wired it to a mounting screw. Can this be right? Does the bulb itself complete the circuit? What happened to green for ground? Bracket
says it is self grounding to any metal, screwed into aluminum strut.
I'm asking because now my turn signals are reversed, and my Prodigy brake controller says I have a short. So either he's wrong, or I've had a visit from a mouse? Trailer is a 1997.
Old 07-24-18, 08:49 AM
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Welcome to the forums.

White is usually used for ground.
That would mean the single wire from the new light goes to the black wire.
The new light gets its ground thru the mounting bolts to the metal trailer.

You need to use a test light or meter to check from your two wires to the metal trailer. One wire should be parking light hot and the other ground. Although there are typical wiring colors..... many choose to use their own coloring/wiring method.

On a trailer.... green is a directional color..... not ground.

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