How to Install an Aftermarket Brake Controller on a 2018 BMW X3

Question:

Is it possible to install a brake controller on a 2018 BMW X3? I have the brake controller plug under the dash and a factory tow package.

asked by: John

Expert Reply:

Yes, you can install an aftermarket brake controller on your 2018 BMW X3, but it will take a minor amount of hardwiring to complete the install. At this time there are no brake controller manufacturers who have designed a plug-in style brake controller adapter for your X3, so what we will have to do is cut the factory plug off under the dash and butt connect the factory wires to the new brake controller wires.

Please note, before you alter the vehicle wiring be sure to use a circuit tester like part # PTW2993 to make sure you identify the correct function of the wires.

From my research, it looks like the factory wires are as follows:

Brown - Ground
Red - Stoplight Switch
Black - 12 Volt Power
Red/Blue - To Trailer Connector

Most aftermarket brake controllers are going to use the same color code which is as follows:

White - Ground
Red - Stoplight Switch
Black - 12 Volt Power
Blue - To Trailer Connector

I attached a diagram to help. Again, I strongly recommend testing these wires with a circuit tester before you make any final connections. Vehicle manufacturers have been known to change up wire colors during production.

If you are in the market for a brake controller, I strongly recommend looking at the Redarc Tow-Pro Elite, # RED44FR. This is a premium brake controller that only leaves the adjustment knob visible giving it a high-end OEM look. I've attached a review video of this brake controller for you to check out.

This installation can be performed pretty easily by most auto shops, but if you decide that cutting and splicing wires isn't what you had in mind, then your next best brake controller option in my opinion is the Curt Echo Brake Controller, # C51180, which simply plugs right into your 7-way trailer connector and is operated via the app from your smartphone. I've personally used this brake controller and I really like the "grab-and-go" design. My only gripe about this brake controller is the fact that it can be easily stolen if you leave it unattended while it is plugged in.

I wrote reviews for both of these brake controllers with more insight for you to check out.