2011 q7 Ac blower problem

My problem is my AC fan blower works fine in cooler weather but when it gets up into the high 80s and 90s the blower runs strong for about two minutes and then it slows down very slow , then off and comes back on about a minute later for like 20 seconds and then it goes back off again and On again and off again. The charge is good and the AC is cold. But the blower has a strange issue. Could it be the resistor? Or is there some temperature control module that keeps cranking the fan up and down. AC compressor keeps turning but the fan keeps cycling up and down.

Do you or can you get the car scanned? It will give you a better of what's going on. That is where I would start.

Yes, I have a scanner. I will first try that. Thank you