If you scan up a few post their is a couple of post as to where to look.Not sure if WI was one of the states that ford thought didn't need them or not. The block heater is on the back end of block on the passenger side .easy to see when you crawl under your truck.

 

Keep in mind that the outlet end of the cord should have a cover on it- Just behind the front tow hook on the passenger side. All 6.0's have the block heater... and all 03 & 04's have the cord. But only some 05-07's had the cord.

 

dark out here now will look tomorrow but the truck is actually from florida so im guessing prob doesnt have the cord

 

I just found mine behind the passenger tow hook zip tied to another wire attached to the frame. 07 f-250. It had a round black rubber cap on the end of it.