my 2002 a4 b6 driver side front and rear turn signals are acting up. They work about every other day. When im using turn signal, hazards, or unlocking/locking the car with the key fob. I know its not the bulb cause they were working this morning, but last night they wouldnt work. its only left side front and rear. everything else works including sidemarkers. The indicators in the dash to not speed up to indicate a burnt bulb nor do I receive any warning lights saying they are out. Any clues?