I just recently purchased a 2007 Ram 1500. It has towing and off road package. I'm going to put an electronic brake controller on it to tow a horse trailer. Is there a "factory" pigtail up under the dash that I can hook up to?

 

Look up behind the parking brake pedal. There should be a blue connector matching the connector on the brake controller.

 

There should be a connector under the dash. The question is, is, do you have the brake wire ran back to the connector? On my 2004 I believe the factory wrapped the brake (blue) wire on the outside of the wire loom running under the truck from the front to the back.

 

If you have a factory bumper mounted 7pin connector, then you have a towing package.
My connector was tucked underneath the carpet and had tape over it. it was up and to the left if your looking at the pedals.
I wouldn't reccomend the Prodigy P3 if you haven't got a controller yet.