I have 2013 Q5 that of late has not been blowing air, either on AC or not. Last summer I had the same issue and I pulled the blower from under the glove box. I initially thought it was the motor controller, but after pulling everything and cleaning and testing, it ran perfect. So I put everything back together. During the winter (I'm in Chicago) there was a handful of times the heat wouldn't turn on. Now that it is summer, it's happening a lot.
Some things I have noticed.........
When it doesn't work , sometimes the fan will only turn up to 7 instead of 12 (the fan still doesn't turn on)
If I leave it on AC, the AC condenser will frost over (plus when it does work, the AC is nice and cold)
If it's cold outside, it has a better chance of turning on than if it's hot

So things that I am thinking........
1-vapor lock of some sort or something to do with the heat affecting the system
2-electrical issue, either in the controls or at the controller motor, be it a loose connection or something like that

Something I'd like to try but don't know how to do it or if it is possible, reset the car to factory defaults, like a hard reset.

Any ideas?

Thanks in advance, Greg

 

FYI:

I fixed my HVAC issue. This is what happened........

On the Q5, in the engine bay are a bunch of cowls, one on top of the other etc. It turns out, that there is a little cowl, called the cowl water deflector that covers the air intake grate and ducting that leads to the blower motor. That cowl was missing, which let in water; a little here, a little there. The water would drip down and collect in the bottom of the blower motor housing. Over time this water caused the metal to rust and eventually seize up. This process was helped by the last major down pour I drove in. So much water came in, that it flooded the blower motor and then found a path to the carpet. On the 2011 Q5, there is a foam thing that covers the space behind the glove box, and upon pulling on that a cup or two of water came rushing out. If you go to Audiparts, under the HVAC system, you can see the exploded diagram that shows the part that covers the intake. It was plain as day when I looked at it.I installed a new blower motor and will install the cowl and that should solve all my problems. So, If you are experiencing water coming into you Q5, I suggest you look to see if your cowling is missing.