Doesn't seem related (weak battery-dash board lights). Try changing the setting on that little slotted screw on the switch housing back/forth, see if that changes anything (look thru owners manual on switching the daylight running lights on/off). Do your headlights come on, just not the foglights/dash lights? You would really need a schematic of this switch to see if they (daylight automatic setting vs. conventional switch operation) share the same relay for turning those lights on/off. Your battery will crap out some day soon when there are temperature extremes, it's just a matter of when.