in order for the electric brakes on a trailer to work, do you need a brake controller or will applying the brakes on my truck automatically apply the trailer brakes?

 

You need a brake controller. It plugs into the little connector under the dash next to the computer diagnostics port.

Actually, you need the "Pigtail" part that usually comes with the truck if it has the "tow package". This plugs in under the dash, then you splice in the corresponding wires from the controller to the pigtail.

Some controllers sell the specific pigtail for your truck, so all you do is plug it in and it's done. No splicing.......

Good luck!

Mitch