I apologize in advance if this post is too long or includes too many unneccessary details. I am just absolutely stumped and not sure what to do next with this problem on my very low mileage (55k) 2015 A5 Quattro Premium Plus S-line Coupe.
So the title pretty much sums it up... but here are few more details on how it occurred and then the troubleshooting steps I have taken thus far. Climate controls seem to be functioning just fine, both driver and passenger sides can be adjusted individually, upper/mid/lower can be selected and no "check engine" lights or other warnings.
1. Checked all fuses related to Climate Control/HVAC system (all were good, replaced the 40A blower motor fuse just in case)
2. Removed glovebox to access blower motor and regulator. Tested output voltage from reg to fan motor, nothing present. Jumped 12V directly to the 2 wire plug going directly to fan, fan spun up just fine. After some googling, ordered a new regulator as that seemed to be a fairly common issue.
3. New regulator arrived, installed, didn't work. To make sure the new part was indeed good, researched how to test it in which both it and the original both passed in working order.
4. Stumped...pulled every single fuse in all 3 fuse boxes (just for fun of course) not a single blown fuse.
5. Considering interior had just been detailed (due to a minor coffee spillage on center console), I looked closer to all the controls, etc. with a flashlight and saw that there is actually a tiny little vent in the middle of the Climate Control panel and inside of it I could see a bunch of dirt/debris that appeared to have all congregated about 1/4" from the outside edge of vent, as if liquid spray cleaner had been applied and possibly it had been brushed and bunched it all together.
6. Googled how to remove the climate control panel and it showed requiring "special removal" tools....NOT! I popped it out with 2 standard hooks that everyone should have.
7. removed all the screws from the back side to remove the tiny blower fan in the climate control in which the impeller blades were just caked with dirt/debris. Separated the panel from the circuit board. Cleaned the plastic panel thoroughly as well as the mini-fan. Reassembled and plugged the wires back in and the mini-fan spun up just fine as soon as ignition turned on, but still no fan output.
Not sure what to try next other than taking it to a dealer (few hour drive 1-way and their labor rate is on the steep end), and not sure if a closer repair facility will have the ability to diganose this if it all comes down to the electronics/software.) I believe I have checked everything I possibly can unless I am overlooking something, which I hope one of you who are kind enough to read my post are willing and able to give me some tips on how to resolve this issue.
Thank you and cheers all!