Hi- I have a 97 A4 with a good 115000 miles on it an runs like a charm.... until, recently sometimes when i turn on the left turn signal, i hear this buzzing noise when its engaged and goes away when the turn signal is disengaged... Is it the turn signal relay that i have to replace? sometimes it works, sometimes it gives this crazy buzzing and the signal does not work..... Is it an easy and cheap fix???