Audi Repair: A/C not turning on at all and something is fiizing in engine (overheating) but temp gauge is perfect, ac circuit, dash panel

Question
Hi, I bought an 01 TT 220 hp yesterday.  Everything seemed fine.  Today I was driving, went into the mall for about an hour came out started the car.  A/C or climate control for that matter would not turn on (No display at all) and the car was spilling coolant (fizzing)  Temp gauge remained perfectly fine.  I do not know if I blew a fuse because there is no display at all for the A/C.  Both problems seem to happen simultaneously.  What could it be?

Answer
Hi PJ

Sounds like the refrigirant gas leaked out of the AC circuit, coolant wont 'fizz'  as you say. what colour was the fluid coming out?? if it was red or green then that would indicate coolant but if it was mostly gaseous and oily then that would be the refrigirant leaking out- the oil being the lubricant added to the gas.

start off with the fuses(driver side, on the dash where the door meets the dash panel, you will need to open the door) check all of them and replace as necessary, then move onto the main fuses on top of the battery. if every thing checks out then the best advise i can give you is to have a diagnosis carried out, as that will save you time and expensive guesses,forward it to me and ill advise you on the next course of action.

as for the refrigirant gas it self the best way to check it is at the filling valve, follow the pipes in the engine bay, (the aluminium ones) and some where along there you will find  a valve(looks like a valve on the tyre only bigger) with a green cap, remove the cap and use some thing sharp to press on it, gas should leak out with alot of pressure, if not then that would indicate that it has leaked out and the leak will have to be repaired and the system refilled.