The owners manual might show you how.

Now the new VW beetles require you to
remove the rear fender to replace the bulbs.
Think of that one next time you are behind
one of those new VW beetles.[:@]

And dont try and get any major replacement parts....
They are 2 years out in back-orders....
Thats why so many of them are for sale used....

 

German engineering for you nowadays.
Used to be the best.

 

While it may be as simple as a burned out bulb if all the bulbs check out then the Smart Box is wiggin out and that will require a trip to the dealer to be properly diagnosed and then replaced. This is something that Ford actually has to approve for the dealer also.

Ford will ask the dealer if any of the wiring or harness have been messed with aftermarket parts which is why is suggest the Plug and Play type Sequential to people because if ford see you have cut into and spliced wiring for them they can void that portion of the warranty.

Richard