I can say it took less than an hour to do this blower recall work at the dealer. So doesn't seem like it's all that involved. I'm sure it's something you could figure out how to DIY.

 

So - I took a quick look last night to see if this was doable for any interested who might be having the same issue. For those that have changed the cabin air filter, getting access to the blower motor + regulator appears to be the same - just take off passenger side footwell cover. Its packed pretty tight down there and it seems that a 3 way footwell air tube/vent is the only thing preventing a quick removal/replace. Hopefully this can be circumvented or removed without having to remove dash or glovebox. Blower motor looks easy but control module (I think this is what dealer is calling "regulator - pt # 97062442301) will be a bit more difficult. I am also trying to locate where the resistor plugs in (part number 99965701390) so I can remove and test with multimeter - I am going to feel like an idiot if that was the faulty component here and I could have just fixed this all with a $12.50 part - I am guessing resistor plugs into the control module - can anyone confirm?

As soon as I test resistor, I will either replace or attempt install myself - will let all know results. FYI - current symptoms = all HVAC buttons functional, can hear ducts actuating when fan speed up but no fan speed. AC + Heat works but no fan to push air out. Could this be anything other than blower motor, regulator/controller and/or resistor? Stay tuned

 

I'm no HVAC expert myself, but I will add I had a similar symptom one time on a road trip - the fan just wasn't blowing any air. I was not in recirc mode and it was hot out - mid 80's maybe 90 degrees. It worked again after 30 minutes of leaving it off. Never has come back that was 18 months ago. Dealer couldn't reproduce but pulled several low voltage error codes from the blower assembly. Recommended two things - keep the car charged up via a trickle charger when not driving it every day, and run the AC in recirc mode especially when it's hot outside.
I've done those things and the issue has never come up. To this day I don't know what caused it - but the theory is some low voltage condition caused the blower motor not to run.
Doesn't make a whole lot of sense but maybe that gives you something else to check. Not sure if you have the diag tools to check those codes - must be in some sort of body / chassis link not the main ECM.

 

After first step of new relay install in August 2019, on Friday had the shifter bushing recall and the new A/C blower control module installed to complete the open recalls.

I was surprised it took until February for parts and another letter from Porsche. Also same type of issue happened with previous Saab and Jetta with regards to the blower control module. I am not engineer but maybe they could develop an air intake for the climate control system to avoid having water rush down past the area to avoid the leaks into the cabin. I don't recall Mercedes with this type of issue but maybe any car now days is prone since the basic functions tend to standardize with new cars year after year.

Back to zero open recalls.

 

I'm surprised I haven't received a notice for any of these recalls. Does it matter if you have a warranty or not?

 

Nope. Safety recalls are performed at no charge to an owner and a letter will be sent out to the last known address of where the vehicle is registered. That is why there is an address change form included in the envelope - in case the vehicle has been sold or transferred.