How to Wire Electric Trailer Brakes When Adding 7-Way Connector to Trailer

Updated 03/30/2022 | Published 03/29/2022

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10 Gauge Wire - Blue Primary - Per Foot

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Wiring Kit for Hydrastar Electric Over Hydraulic Actuators

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Question:

I have 2021 Big Tex single axle trailer. I’m looking into adding trailer brakes as mine did not come with any. If read up on what trailer brake, hub Assembly, mounting hardware kits l, and bearing kits that you have been recommending. I believe I understand the process of installation. One thing I am missing is what wiring kit will be needed. My trailer has a 4 flat so I will be needing to upgrade to a round 7 connection plug. Thanks I’m advance!

asked by: Gregg B

Expert Reply:

You would indeed need to update the trailer connector which luckily enough is pretty straightforward.

I'd recommend using the # HS381-9000 which incorporates both a trailer connector and a junction box which provides a secure place to make your wiring connections that's protected from the elements. Cut the 4-pole off, and wire the leads into the junction box. You'd then use a length of # 10-1-1 brake wire to run a circuit to each brake assembly. One wire from each assembly grounds to the trailer frame, the other connects to the brake output circuit.

The color coding of the terminals is as follows:

• Green wire-running lamp circuit
• Black wire-12V accessory feed to trailer
• Yellow wire-reverse lamps (if needed)
• Brown wire-right turn/right brake lamp
• Red wire-left turn/left brake lamp
• Blue wire-brake output to brake magnets
• White wire-grounds to trailer frame