Troubleshooting Trailer Lights Not Working With New 5 Way Trailer Connector

Question:

Bought single unit tail lights which are combination brAke, turn, and lights with 5 wires out of each but both same colours, wiring harness has 5 but black is changed for brown on harness, do I connect black to brown or do I follow totally different

asked by: Luke G

Expert Reply:

For your 5 way wiring connections, you will need to connect function to function an not color to color. When using the Bonded 4 Wire - per foot # 16-4B-1 the green is traditionally as follows:
yellow=left turn and tail
green=right turn and tail
white=ground
brown=running/clearance
Then for your 5th wire, you will run your brake function (traditionally blue). If using electric brakes this wire is connected to your brake controller and then to your brake magnets on the trailer. If using as a reverse lockout for hydraulic brakes, you will use the reverse light power and then connect to the solenoid on the trailer side.

If your 5-way has a black wire, that may be used as any of the functions, so you will want to pay attention to the location and function.

I've linked a photo to help with the wiring location based on these colors to assist. I recommend using the Deka Heat Shrink Butt Connector - 16-14 Gauge - Nylon Insulation - Blue - Qty 10 # DW05744-10 for the installation. If you find that your lights are not working after installation, it is most likely a ground connection issue and you will want to make sure the ground wire is connected to the trailer frame bare metal to metal and free of corrosion and debris.