Wiring Stop Turn and Tail Light Circuits to a Trailer Light

Updated 10/01/2012 | Published 09/28/2012

Question:

My trailer lights only have a single wire. Do I connect both the taillight and turn signal wires to this connector, or something else. Photo attached.

asked by: Juan O

Expert Reply:

Your trailer lights should only have one wire if the light serves only one function (tail light, marker light, stop/turn). The white wire shown in the photo that you attached is a ground wire and will not be connected to the tail light or stop/turn circuits. The bulb attached to your light housing looks like an 1157 bulb, which is a dual filament bulb that has two contacts for two different circuits.

You should have two wires on the back of the light housing, one for the stop/turn circuit and one for the tail light circuit. If you remove the mounting screws, then you should be able to find these wires coming from the contacts of the light bulb.

expert reply by: John H