Passat 2001 TDI.
Smoke started to appear out of air vents, Investigated and found Hazard unit burned out. Got new one and the same happened the next day. No fuses blow. Left in to Vw Dealer and he is scrating his head, has tried numerous things including the indator switch on steering column. No sign of burnng or shorts on any of the lamps or cables. When a new unit is instlled will work for a short time and then burn out. It burns out evan whne the indicaors are not being used. Any ideas.