I had a slow leak (2005 N/A) somewhere. My A/C would only blow lukewarm air. A buddy here on the forum has a set of A/C test gauges/manifold and checked the pressures (2-one high and one low). I was low on R-134a.

He had a can of R-134a and topped it off. Worked great. For 6 months.

Bought a can of refrigerant at AutoZone and topped it off again. Worked great. For 6 months.

OK, I decided. I have a leak. Bought a can of R-134a from Amazon with "Advanced Leak Sealer":

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Has been providing Crystal Nipples for over a year.

I decided I had no issues with adding refrigerant since the system had never been to zero pressure and there was no chance I had contaminated the system.

BUT-and here is where this thread comes in-when the ambient temps go over ~ 90 degrees F, the fan runs full-tilt when the car is stopped/idling. Once I drive for 2 minutes, it slows down. If I stop for more than a couple of minutes, it goes full-tilt.

I don't have a problem with this behaviour. A/C works. Engine temps are right where my -10 degree C "Fan Mod" says it should be.

So, the moral of this story is: If your A?C is not blowing cold air, have a shop/tech check the operating pressures. NOT static (engine off) pressures. These pressures are pretty much universal-check YouTube.