Can 4-Way be Spliced Into Trailer That Has 7-Way
Question:
Ive got a small cargo trailer with gvwr around 2.5K. It has electric brakes installed, but obviously not mandated given GVWR under 3K. It came with a standard 7-pin connector naturally. My question is, Id like to add a second 4-pin connector to the trailer side so that you have option up connect to a vehicle that lacks a 7-pin connector and only has a 4-pin one or the other at single time, not both obviously. Can I simply take a 4-pin connector like this one and splice into the existing 7 pin wires that already exist on trailer, and then Ive got dual plugs on the trailer? I realize there are vehicle adapters to convert 7 pin to 4 pin, but Im looking for a seamless way to have dual options to connect directly to vehicles with 4 or 7 pin. Of course Id lose the electric brakes when running 4 pin, but again not mandated since GVWR is under 3K.
asked by: Justin
Expert Reply:
If you don't want to use a vehicle adapter like the Mighty Cord Trailer Connector Adapter - 4-Way Flat to 7-Way RV Style # A10-7084VP on your vehicle with a 4-way to adapt it to your trailer's 7-way, then yes, you can splice into your trailer's wiring to add a 4-way if your like.
You can use the trailer side connector you mentioned, the Hopkins Endurance Easy-Pull Harness with 4-Pole Flat Trailer Connector # HM38136.
To splice it you can connect your wires with the Deka Heat Shrink Butt Connector # DW05743-5.
I've added a link to a video install for you to check out as well.

Products Referenced in This Question
Mighty Cord Trailer Connector Adapter - 4-Way Flat to 7-Way RV Style - 12" Long
- Trailer Wiring
- Wiring Adapters
- Single-Function Adapter
- 0 - 5 Feet Long
- 4 Flat
- Plug and Lead
- 7 Round - Blade
- Mighty Cord
more information >
Deka Heat Shrink Butt Connector - 22-18 Gauge - Nylon Insulation - Red - Qty 5
- Wiring
- Wire Connectors
- Butt Connectors
- 22-18 Gauge
- Deka
more information >
Hopkins Endurance Easy-Pull Harness with 4-Pole Flat Trailer Connector - Trailer End - 25' Long
- Trailer Wiring
- Trailer Connectors
- Trailer End Connector
- 21 - 30 Feet Long
- Plug and Lead
- 4 Flat
- Hopkins
more information >
Product Page this Question was Asked From
Hopkins Endurance Easy-Pull Harness with 4-Pole Flat Trailer Connector - Trailer End - 25' Long
- Trailer Wiring
- Trailer Connectors
- Trailer End Connector
- 21 - 30 Feet Long
- Plug and Lead
- 4 Flat
- Hopkins
more information >
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