BobR

O.K. Thanks Steve, I'll do that tomorrow and update the post accordingly.

I have now replaced both the blower motor and the control unit without success! Is there a next step to fault find please?

Hi Steve Q, thank you so much for your help my friend.

I have an Audi A6 C5 Avant, 2005. Recently the Heater Fan stopped working and having gone to my local Audi garage, they diagnosed a faulty motor and then informed me that due to the year of my car, they can no longer obtain the parts! I managed to buy a new pattern motor form the Internet, which the garage agreed to fit. This hasn't sorted the problem! They now say that it may be the Fan Control Module, part no. 4BA 820 521. I've searched for this number on the Internet but keep getting directed to the Heater Blower Resistor part no. 4BO 820 521. I'm new to this forum, so please forgive any mistakes on my part but PLEASE can anybody help me?