turn signal dilema

[Robert Cuttler]

I've got 1999 A6 with an intermittent right front turn signal.  All other right side bulbs 
flash except the front, including the side fender bulb.  The wiring diagram shows 
power from the turn signal switch going to a connector then branching out to the 
side marker bulb and the front bulb.  Most likely culprit seems a bad connection at 
this connector or at the bulb or a bad ground at the bulb.  Problem is, when the front 
bulb ceases to flash all I have to do is turn on the headlights and it will immediately 
function appropriately.  What do the headlights have to do with the turn signals?
TIA
BOB