Can You Convert 4 Way Plug To Work With Trailer Brakes?

Updated 03/17/2026 | Published 03/15/2026

Products Featured in This Question

Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires

(3551)

$118.67

Curt Trailer Connector Adapter - 4-Way Flat to 5-Way Flat - Vehicle End

(107)

$20.20

Question:

Can you convert a 4 pin plug to work trailer brakes?

asked by: Jon L

Expert Reply:

Hey Jon, yes you sure can! And it's not too difficult either.

If your vehicle already has a 4 way flat on the back, you can just install the # ETBC7 which converts it to a 7 way to be used with trailers that have electric brakes. Basically the 4 way plugs into this kit, then you run a few wires up to the battery and brake controller. You'll need a brake controller as well if you do this kit. Let me know what vehicle you have as there may be a custom fit plug and play option.

Now if your trailer actually has surge brakes which are common on smaller boat trailers, then you may not need a 7 way and can likely use your 4 way or convert it to 5 way with a single wire that needs to be added with kit # C57187.

Just let me now what vehicle and connector you have, and what trailer connector you need to match it up to. I'm here to help!

expert reply by: Andrew N