Towing Issues: Ford Escape 2004 trailer wiring harness, trailer wiring harness, factory wiring harness

Question
Don:
I am looking to add an aftermarket tow package.  For the wiring harness, the aftermarket ones plug into the tail lights.  Ford's website offers a harness that "is made to plug into the factory wiring harness at the rear of your vehicle.  I have the Helm shop manual but it doesn't have wiring diagrams.  Is there a separate harness hidden somewhere for a tow package?  If so, where?  I have been unable to locate it.  If not, does the Ford harness connect in the same way as the aftermarket harnesses?  
thanks for being there.
Roger

Answer
I have had GM trucks, so don't know for sure, but if your truck doesn't have a tow package, then I would think any harness would plug into the trucks harness at the back like the aftermarket ones.  

Either harness should come with instructions.

I have actually found U-Haul stores to be very good at having the stuff you need, or go to a business that sells lots of travel trailers.

Don