Following this post too. I am dealing with the same issues with mine and in the process of getting all of this figured out. My part number is 2C7T-15K602-AF. Truck is a 2002 F-250.Thanks again for your help.
There's not a lot of info out there so I'm thinking of making a youtube video throughout this process to help others maybe... But, when you take your VSM out be sure to check the three always hot wires on the harnesses and the one ground wire. Ensure you've got power to it that seems normal.
Other than that, I am also well aware of the difficulty of finding a replacement part. I found this website called RepairLaboratory.com that repairs them for $180. I'm a little bit sketched out by them though. Maybe I'm being too critical but I want to know I'm not going to screwed...