Converting a 7-Way Blade Style Trailer Connector to Work with a 7-Way Semi-Truck Connector

Question:

i wired everything up properly but have no brake light, found out there is a separate pin just for the brake lights. i wired that pin up to the green and yellow lines and found out i had brake lights, but if i used the directional basically my hazards were on. no matter which direction it was on. i could use some help trouble shooting this, can find anything online.

asked by: James L

Expert Reply:

The problem that you are having is due to the fact that the 7-Way for a semi application is wired differently then a 7-Way on a vehicle. On a 7-Way blade style the turn signals and brake lights are combined onto the same circuit, one for each side. A semi 7-Way as you have said has a separate circuit just for brake lights.

What you need is a converter that takes the combined signal and separates it out so you are left with right turn only, left turn only, and brake light only. There is a special converter just for this, # 118158.

The combined left turn and brake connects to the yellow input wire, the combined right turn and brake lights connect to the green input wire. White is ground. Everything else bypasses the converter.

On the out put side you will have yellow for left turn, green for right turn, and red for brake lights. I have linked a video demo of this converter for you.

expert reply by: Michael H