Yaris mirror heating issue

I've got a Yaris too, though I can't remember what year it is right now. I had a similar problem last winter. For me, it ended up being a bad connection somewhere in the wiring. Check the wiring loom where it enters the door, those are prone to damage.

Thanks for the quick reply! Could you be a bit more specific about which connection you're talking about? Where exactly should I be looking in the wiring loom?

Yeah, sure. For me, it was the cable or plug connection of the heater element in the mirror itself that was defective. Honestly, I tried fiddling with it, but eventually gave up and took it to a shop. Best money I spent!

Okay, I think I'll follow your lead and take it to a workshop then. I saw some reports that the repair would cost around 95€. Thanks for the help!