Burning Smell Coming From Fans

I’ve got a 2014 A3 Sline 2.0l sportback. When it’s cold outside (frosty) and I use the fans to de-mist the windscreen, there is an awful, strong burning smell coming from the fans on the dash (the ones facing you). I realised it’s just the fans in the left ie the one next to the passenger door and the left of the two centre ones. Mechanic looked at it, changed the air filter, checked the fan motor and all seemed ok. It did it again on Tuesday when it was freezing cold. Booked it into the audi dealership to do a diagnostic and they can’t find what’s wrong with it?! No faults registered on the computer and all components look to be fine. He said other than dismantling the dash to look for a needle in a haystack which is labour intensive and costly, there’s nothing they can do.
Any ideas?! It’s driving me mad! Of course it didn’t make the burning smell when they looked at it. Typical!

Chris-P said:

Have you changed the pollen filter?

That lives behind the glovebox.

Click to expand...

they checked the pollen filter and said it’s fine. Only happens when it’s really cold outside but obviously when it’s icy that’s when I need to use the fans! Strange that it’s only one side??