We had the same problem on our first trip in our 2010 2551. Kermit solved the problem with a phone call.
The problem is the dimmer switch for the dash lights located to the right of the headlight switch. When you rotate the dimmer switch up to the brightest and then further until it clicks, this turns on the map lights above the rearview mirror and also provides continuous power to the step lights even with the doors closed. If you then use the on-off switches on the map lights to turn the map lights off, then the step lights are still powered. So, your dimmer switch is probably in the full bright position. I leave the on-off switches on the map lights in the on position and use the dimmer switch to turn them on and off, this way I know when the power is on continuously to the step lights as well.
Kermit thought that Ford had made a change in the dash light wiring to cause this situation, and that it might be better to have map lights without individual swiches..
Hope this helps, Bob A
