Aircon ?

With all the other rattles etc that age can bring....

Recently (probably since after my rad replacement) I've a bit of an annoying occasional squeek or something like a tape player style noise when the fan is on setting one!

The aircon does work on setting 1 (and after that), but it grates a little....not so noticeable on setting 2 and not at all beyond that. I'm not sure if running the thing on full for a while seems to settle the whole thing out (like italian tuning), perhaps a little ?

Anyone had their car develop this kind of thing.

Its still fairly cold but never had any kind of aircon maintenance from new and its always been fine, piping hot/cold although I have had a fault code forever about the range of motor movement or something from outside.

Just wondered if its worth doing much about it ? Its not like its been skimped on with regard to cabin filter etc so I wouldn't imagine it would be due to that.

Tried to see if its from outside the car from the rad fan side but its no louder there.

If stays on after the car is on and kind of dies off once the car is off. What the hell is the noise !