After Replacing Trailer Side 4-Way Wishbone Harness with Non-Wishbone, Running Lights Dont Work

Question:

Flat 4 wishbone was damaged by letting dump gate down. All lights on trailer worked great til this happened. I wired a standard flat 4 to trailer. Green to green, yellow to yellow, white to white, then the single brown to both browns. Lights for turn signals both sides, brakes, and 4 ways work. Tail/ running lights do not. Why? Do I need the wish bone plug?

asked by: Steve

Expert Reply:

The issue is likely in how the 2 brown wires are connected and then connected to the single brown from the new 4-Way. You basically need to make the 2 running light wires into one and then butt connect to the single brown.

You could use the Quick Fix, # HMC20031, twist the two running light wires together and then put the newly combined wire in place. Or you could go ahead and swap the 4-Way for a wishbone, # A20WB.

There also could have been a short that fried the lights when the original wiring was broken. Use a separate 12 volt battery to power the lights (using their wires) to see if they light up. If they do not then you likely will need to replace the lights.

expert reply by: Michael H