Changing Trailer 4-Way Wiring to 7-Way Wiring for Extra Function and Compatible Connector to Truck

Published 10/03/2018

Products Featured in This Question

16 Gauge Primary Wire - Black - Per Foot

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Hot-Line LED Utility Light Bar - Submersible - 13 Diodes - Clear Lens

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Ring Terminal - 12-10 Gauge Wire - 3/16" Ring ID

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7-Way Round RV Style Trailer Connector - Trailer Side

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

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Question:

Hi, I have a 2014 GMC Sierra that has both a 4 and 7 pin female connector. I am wanting to switch my boat trailer, which currently has a 4 pin male plug on it, to a 7 pin male plug. My reason for doing this is so I can mount two led lights on the trailer to use only as reverse lights. I am not sure where to connect the 4 pin wires to the corresponding wires on the 7 pin plug. Also, Do I run both positive leads from the lights to the reverse lights wire that is on a 7 pin? Will I ground the wires on the trailer or to the 7 pin? Are there any wiring diagrams that will make this easier to do?

asked by: Ryan R

Helpful Expert Reply:

To switch your boat trailer from a 4-way to a 7-way connector, I recommend using the 7-Way Molded Trailer Wire Connector, 6' Long # H20044 along with heat shrink butt connectors # DW05744-5. You will ground the white wire to your trailer frame using # 44-5310A and then connect the running lights, right turn/stop, left turn/stop, and reverse light. To the reverse light (yellow wire on # H20044) you will connect # 16-1-1 wire sold by the foot to lead to your trailer reverse lights that you will want to be submersible for your boat trailer. The 12V (black) and Brakes (blue) wires will not be connected so you can cap or cut them and tape out of the way.

You can instead use Optronics7-Way Connector - Trailer End # A7WCB. I've attached a video of this installation. You will simply match function locations. I've also attached an article to assist.

I recommend the Hot-Line LED Trailer Backup Light - Submersible - 12 Diodes - Clear Lens - White # 328-003-6017W for your LED lights and you will want to connect both if you are using two to the # 16-1-1 wire with the left over heat shrink butt connector from the kit above. Then you will ground the negative wire on each light to the trailer frame.