peugeot 306 electrical problem?

the heater on my 306 recently stopped working along with the air con unit having checked all fuses and where ok i assumed there was a wiring problem. then the heater came back on but wont turn off and will not change from hot to cold and when the heater comes on the air con shows as on but blows how air also the passenger electric window will not work one way and is showing as only getting 4.5volts to the motor
any ideas
thanks