Remembering why I
dislike working on
AO Silver Member
Join Date: Sep 2001
Re: air-con problems
Start with either the sensor...or possibly the wiring to it. It's an NTC thermistor, so if it goes open circuit (or the connections to it do), then the system will assume it's very cold.
If you can get at it, probably the quickest way to check would be to unplug the sensor and short out the loom connector pins. Car should then think it's got very warm all of a sudden. If no change, it's the wiring most likely.
Could conceiveably be the ICS itself, but it's usually the simple stuff that goes wrong.