Can anyone help. A/C doesn't work when interior switch pressed in, although switch lights up. External temp sensor displays -25C, even in summer. A/C will work if connecting a wire direct from battery to compressor. Internal climate control temp settings also don't work properly (occasionally blows hot air out when set at 18C). Any clues?

If the cars temp guage is showing -25C then get a new sensor. Its on the drivers side mirror.

Basically the aircon wont work until the temperature is over 5C-7C.