Parts Needed to Add 7-Way to 2025 BMW X3
Updated 11/07/2025 | Published 10/22/2025
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Question:
Im am wanting to add a 7 pin wiring harness to my 2025 bmw x3. Can you suggest one please? I have a trailer with brakes and reverse lights. That is why the need for 7 pin.
asked by: Gregg P
Expert Reply:
Hey Gregg, welcome back! The first thing you need to do is add a 4-way. You can use the Curt # C59236 which splices in or the # 119250KIT which uses sensors that clamp onto your vehicle wiring. Once you have your 4-way installed you can use the # ETBC7 to upgrade it to a 7-way. This comes with the adapter, wiring, breakers, and everything else required for installation.
Do you already have a brake controller? If you don't, I recommend the Redarc Tow-Pro Liberty # RED52VR. The main unit installs behind the dash so only the control knob is visible. This means it won't take up space and will have a nice clean look in your X3. The knob controls the braking power and acts as the manual override.
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Product Page this Question was Asked From
Roadmaster 4-Diode Universal Wiring Kit for Towed Vehicles - 7-Way to 6-Way Coiled Adapter Cord
- Flat Tow Wiring Harness
- Splices into Vehicle Wiring
- Diode Kit
- Universal Fit
- 7 Blade to 6 Round
- Roadmaster
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Gregg L.
11/2/2025
Thank you for the brake control suggestion. Does the Redarc come with everything I need to install it? The battery for the x3 is in the rear. Will it have a long enough wire to run from the back to the front?