strange a/c related "problems"

[VolvoC70T5]

Last two months i have experienced one strange thing.

Lets say ambient temp out is 30 deegrees, which is also written in temp display and when i turn a/c on, temp on display starts increasing to 40 on the display....stays the same untill i turn the a/c off, then the temp on display slowly within 5 mins comes back to real 30 degrees.

What would this be with this strange symptoms?

I have the car for two years now, and since beggining i had high pitch sound when turning the car engine on, which was more affected when using a/c.

Also have from beggining hissing sound at the passenger legs when a/c was on.

When i turn off the a/c, that high pitch sound appears again, for cca 5 secs.

Ac works completly fine thou.

Anyone has any ideas with the temp display wheb ac turned on?

Car is c70 01 me7 t5

[Ozark Lee]

Mine always jumps a bit when the A/C is on. It is due to the proximity of the ambient temperature sensor to the condenser coil. It tends to be worse in city driving than on the highway where there is more ambient airflow around the sensor.

...Lee

[VolvoC70T5]

Few celsius + is normal i know as i also had some temp jump when turning ac on - for 1 or 2 celsius more, but 10 more than real is something wrong....it does not matter if i drive slowly or on ac, same temp difference....

Dont know what to look after, to repair it - anyone?

Are the ambient-out temp sensors located on both sides under front bumper? one on each side