How to Wire Black and White Wires on Side Markers Using Wishbone Harness A35W42B

Updated 09/17/2019 | Published 09/15/2019

Products Featured in This Question

35 Ft 4-Way Trailer Wiring Harness - Wishbone Style - 42" Ground

(833)

$22.90

35 Ft 4-Way Trailer Wiring Harness - Wishbone Style - 42" Ground

(833)

$22.90

Deka Heat Shrink Butt Connector - 16-14 Gauge - Nylon Insulation - Blue - Qty 5

(1062)

$7.32

Optronics LED Clearance or Side Marker Light w/ Reflex Reflector - 6 Diodes - Oval - Amber Lens

(3932)

$7.06

Question:

My markers have red and black wires. The main tail light wires are green/ brown and yellow/ brown. Where do the red and black wires go?

asked by: Thomas A

Expert Reply:

To wire a side marker or clearance light that has a two wire design like # MCL31AB, the white wire needs to be grounded to your trailer frame while the black wire which is for power needs to be connected to your running light circuit.

On a wishbone style trailer harness like # A35W42B the running light circuit is split into two which is why you see the green/brown on one side and yellow/brown wire on the other side of the trailer. You can simply connect the black wire coming from the side marker to the brown wire on either side using a butt connector like # DW05744-5.

expert reply by: Carla M