Most trailer brake controllers will come with a mounting kit that will attach to your dashboard easily. You can install it on the dash or underneath if you want to keep your dashboard free. The brake controller should also come with the wiring needed to set it up, this is the most difficult part of the installation. There will be full instructions on how to do this. If you want to pay a professional to install your trailer brake controller then this can cost anywhere between $60 to $350 depending on where you go. It’s important to install the brake controller correctly.