2002 Cadillac DeVille - A bunch of electrical issues

electrical problems all started at same time - push button & fob trunk open - gas tank button - door lock button & remote lock fob * note** the head lights come on when remote fob is pushed to lock /unlock - interior lights - dome lights from buttons or door open - door lights however windows - cruise cont. - dash - heater / ac - sun roof - mirrors - and wipers all work
can anybody tell me what is common to these circuits? Or has anyone seen this before?


first thing I tell anyone that asks about weird electrical issues on a car: check the battery. Make sure the battery is good and the connections are tight and clean. Especially if this has the side mounted battery posts that GM loves to use.