Product review (5 stars): perfect fit for my Kitchenaid KUDC10FXSS6
Just to clear up any confusion related to the question I asked, this item did come with the wax motor that operates the soap dispenser door.  It is a complete unit, perfect fit for my Kitchenaid KUDC10FXSS6, and works great.  If you are struggling trying to figure out which part of dispenser unit is broken, just buy this whole unit and save yourself time and money.

The job took me about 30 minutes and I'm very happy.

I used a T15 driver for the door screws, a 3/16th socket for the dispenser door screws, and a flat screwdriver to pry back the mounting tabs.