This is a common problem from what I have found. Its a factory defect although Ford will not provide any help with. The Dealer is worthless to, all they want is to have you buy a new one for $ 890.00 plus installation.
Here is the simple and best answer: take out the gauge cluster and ship it to United Radio in Syracuse, New York (315) 446-8700.
$ 155.00 to $ 175.00 and they go through your cluster and repair the issue.
Took them 2 hours and there you have it.
Nice people and professional too.