When I switch my car from warm defrost air to just cool outside air my car makes a really louid clicking noise for about 2 min then stops... I thought at first it was the ac but the ac was not on and I just had it looked at so I was wondering if it could be the blower... because last winter I had an episode to where I turned the heat on and nothing came out of the vents... any help would be great.

First:
https://www.askmehelpdesk.com/cars-trucks/when-asking-about-your-vehicle-303903.html

so I was wondering if it could be the blower
Second, is the blower not working?
Some clicking is normal as the system switches but it shouldn't continue for two minutes. That could be a mode door actuator motor binding.

Ok it's a 2006 chevy impala with a 3.5 engine in it... the blower is working and blowing air just not as strong as it use to and it is making a loud clicking or klunking noise when I switch from defrost to just the vent to blow air in from the outside. I do not know a lot about cars but I would like to have an idea about what is wrong before I take it to have it looked at. I know its not the air because I just had it looked at and this noise has only happened twice to me and only when I go from defrost to just the vent.

One of the blend door servo motors (under your dash) is going bad.
Probably trying to make a go of it but just can't do the full swing. This will need to be checked out.

I took it to the dealership and It would not make any noise for them they could not find anything wrong because it would not make a noise for them to look at,