Ac Temperature Sender ?

[ALBERTO]

Hi my CLk 430 1998 has now a AC problem, the temperature setting is not working prorly I mean It cool too much or it heat too much.
Just to tell you i changed filters and i replaced r134a with the correct amount of oil as i have the vacuum pump with the AC system.
I think I have a problemwith both external and Internal temerature sender as the ext shon about 3 C more than the real and also i the internal i cjeck with teh menu is always 2 or 4 C more than the REAL internal temp even afterny h of driving......
Do you have idea about?
Please tell me where are situated the 2 sender as my car is impossible to drive now
thanks a lot guys
alberto