The switch that controls the heated mirrors on my 06 is flashing. Switch will not power on or off, it just flashes.

I took the truck to the shop to have them pull the blower motor down and remove the recirculate door, since it is broke. I get the truck back and the mirror switch is in the flash mode. Mirrors are not warm, which tells me the grid is not working. The mechanic re programmed the doors and now I get a flashing switch, that I did not have before I took the truck in. I do not know why he had to re program. Any clues why the switch is flashing? I have a hard time believing the switch flash would exist had I not taken the truck in to the shop!

What do you think?