Upgrading 4-Way to 7-Way Trailer Wiring on 2014 Subaru Outback with No Brake Controller
Question:
4 pin to 7 pin adapter for 2014 Subaru Outback: I am planning to convert my previously installed 4 pin Hopkins connector to a 7 pin/4 pin connector. My trailer Taxa Tiger Moth has an Autowbrake wireless controller on it. I saw the 2011 Subaru Outback video for installing a brake controller and Hopkins 4 pole to 7 pole adapter videos on your website. I am interested in using Hopkins part # 37185 for the 4 pin to 7 pin/4 pin connector unless there is a different product you would recommend. I have a Draw-tite class II 1-1/4 inch hitch that I previously installed, but plan to buy a Draw-tite class III 2 inch hitch part # 75673. Im assuming that I can use the previously drilled holes for mounting the new hitch? For additional parts, what type of circuit breaker should I get for the 12 V connection? 40 amp - Part # 9510? When installing the wires, should the ground attach to the chassis near the hitch with a self taping screw? Watching the video, it looks like the 12 V wire is split, attached to the circuit breaker and then attached to the battery. Is this correct? It looks like the two additional wires for the brake controller would not be used. Is this also correct? Are there any additional parts I will need for this project? Thanks!
asked by: Brian
Expert Reply:
It sounds like you are on the right track with everything here. You can use the Hopkins part # 37185 to convert your 4-pole connector to a 7-pin connector, but this is just the adapter. We've built a complete kit for this exact situation and it includes everything you need to have a fully functioning 7-pin trailer connector minus the in-cab brake controller, part # ETBC7L. This is what I recommend for you and it comes with a better 4-pin to 7-pin adapter.
You will want to run the 12 volt battery charge wire up to the engine compartment, attach it to the silver side of the included 40 amp circuit breaker and you will have enough wire left over to run an additional wire from the copper side of the breaker to the positive battery terminal. I attached a video that overviews this kit. You will want to ground the white ground wire from the adapter to the vehicle frame.
For the trailer hitch, you can absolutely use the existing holes you drilled to upgrade from the Draw-Tite Class II trailer hitch to their Class III trailer hitch, # 75673. They use the same bolt pattern and the new hitch will come with new hardware for you.
The only other component you will want to complete this install is the no-drill long bracket # 18136. this bracket will attach to the crosstube of the trailer hitch and provide a mounting point for the 7-way connector bracket.

Products Referenced in This Question
- Accessories and Parts
- Trailer Wiring
- Mounting Hardware
- Brackets
- 4 Round
- 5 Round
- 6 Round
- Tow Ready
more information >
Adapter 4-Pole to 7-Pole and 4-Pole
- Trailer Wiring
- Wiring Adapters
- Multi-Function Adapter
- 4 Flat
- Plug and Lead
- 4 Flat
- 7 Round - Blade
- Hopkins
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Draw-Tite Max-Frame Trailer Hitch Receiver - Custom Fit - Class III - 2"
- Trailer Hitch
- Custom Fit Hitch
- Class III
- 600 lbs TW
- 4000 lbs GTW
- 2 Inch Hitch
- Visible Cross Tube
- Draw-Tite
more information >
Product Page this Question was Asked From
7-Way RV Upgrade Kit for Trailer Brake Controller Installation - 12 Gauge Wires
- Accessories and Parts
- Trailer Brake Controller
- Installation Kits
- etrailer
more information >
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