the relay is behind the hazard light button in the center of the dash. you can hear the clicks of both the hazard lights and the signal lights coming out of that area.
to change out the relay, take out the radio, and you should have a pretty easy access to the relay switch right above the radio unit.
if you need precise instructions on how to remove the radio, do a quick research and you should find the answer. if you've already replaced the radio with an aftermarket unit, this should be a lot easier.
The turn indicator relay in an Audi TT is integrated with the hazard switch. To replace the relay you would need to replace the hazard switch.
in my 2001 A4, it was the hazard light switch that had to be replaced. maybe thaqt's your issue also
behind the hazard button, its built as complete assembly for Turn/hazard signal
its the hazard switch, its all one unit
The turn signal flasher relay is located behind the hazard light switch, which you can access by removing the associated dash trim panel
It's in the hazard warning switch. You need to replace the switch.
bad bulb, relay, wiring, turn signal switch
The hazard relay is the turn signal relay as well. The grinding noise is actually the relay buzzing trying to engage. Mine made the noise occasionally and now the turn signals do not Work at all. TIME TO REPLACE THE RELAY.
http://www.audiforums.com/m_146946/tm.htm
This seems to be a cammon fault with VW/Audi cars. U will need to replace the hazard light switch mechanism which contains the switching contacts. I had to replace same in my last cars (VW/Audi)
I would like to know where is the horn relay & alarm horn to replace & fix on my audi tt
you go.... and replace it!