This just started on my 2011 Santa Fe. When car is running and the light switch is on either of the auto mode or in the off position, all of the blue lights (mileage section of speedometer, clock, heater controls, doors, etc) react to blinker and brake. when blinker is turned on these flash, when brake is pressed, they all dim.
when the light switch is either in the on position or the parking light position, everything is normal.