Can Running Light Circuit of Trailer with Two Wires Connect to Single Wire Circuit

Question:

I need to attach a new 4 flat due to damage to the old and when I looked at the wires on the trailer I have 1 yellow, green and white ground wire but 2 brown wires. 1 is brown with green stripe and the other is brown with yellow stripe. I assume those wires are for the running lights on each side of the trailer. Can I splice these wires together and connect them to the 4 flat? I have surge brakes on the trailer but have read that this may cause me problems when trying to back the trailer!

asked by: Doug

Helpful Expert Reply:

The type of 4-way wiring your trailer has is referred to as wishbone wiring where there's two wires for each side of the trailer's running light circuit. This easily can attach in the way you described where both wires run to a single running light circuit wire.

Normally with surge brakes there's two ways to allow it to back up without the brakes locking up. You can install a reverse lock out solenoid (you may have one already) but this runs to the reverse light circuit of the vehicle and prevents the brakes from locking up when activated. Or you can install free-backing brake assemblies which basically just don't work when the wheels are rolled backwards.

helpful expert reply by: Jameson C