Hi all,

First off, happy new year to everyone. All the best for 2018!

My car is a 2013 A6 2.0 TDi SLine. When setting off with a cold engine the other day, I noticed a relay "ticking" noise coming from behind the dash on the right hand side. It's the same noise I associated with the supplementary heater switching on in the mornings when I turn the cabin temperature up, except now it kept ticking frequently (but irregularly) up to several times a second until the engine was warmed up. After that the noise went away.

For what it's worth, the ticking noise does seem to be road-bump-sensitive, i.e. potholes and rutted roads seemed to set it off, hence why I'm starting with the relay.

I know the root cause could be many things, even a temperature sensor. But the first thing I wanted to check was the supplementary heater relay. Can't seem to find any information on the location of the damn thing though.

I've checked the manual and the fuse box (and searched the web) and I'm reluctant to start dismantling the dash until I know more so can anyone help? Also, has anyone had this issue?

Thanks for any help!