problem with a/c thingy

[aust92pearl]

today when i started the pearlie up when i turned the ignition on the a/c thing beeped and consequently the temperature readout doesn't work.
everything else works eg. a/c, fans, presumably the heater if it wasn't bypassed and still shows temp on it when a/c and heater is on. but when pressing the temp button it doesn't do anything . when i first turned it over it briefly flashed 14* just before it made the beeping noise . any ideas on what it could be ?