My '04 Sonata parking lights (& dash clock) start rapid pulsing about ten minutes after turning them on. All systems fine before condition occurs. No apparent issue with directional flashers even while pulsing is going on.
kmurphy129

 

Seems as if the alarm system is trying to activate (without horn) Does your horn work? Does pressing the buttons on the key fob remote have any affect? Are you able to drive it? What makes it stop?

 

I'd check the charging system. Does the pulsing go away as the RPM's go up? Have the alternator inspected.