first off this isnt my A4 its my dads 99 jetta with the 2.0 ABA engine. he bought it during winter so he didnt really have a chance to test the A/C, but anyways latley i drove it and noticed that the A/C compressor dosent kick in until about 2k revs. after that its blows cold. ive checked the refrigerant level and made sure teh surpentine belt is tight, what else could be a possible problem. also just recently like last night my dad told me the dosent even blow cold air anymore. is this a sign of a seized compressor, possilby a bad clutch?

 

a simple but effective initial test is to check temperatures of the refrigerant system components and lines by touching them with engine at operating temperature and the aircon on the touch test should reveal the following.

a hot compressor'
a hot high pressure refrigerant line from from the compressor outlet to the condenser.
a hot condenser on the inlet side.
a warm condenser on the outlet side.
a warm liquid line from the condenser to the evaporator ( before the expansion valve or fixed orifice tube ).
a cold evaporator outlet line.
a cold low pressure refrigerant line to the compressor inlet.

if the results from the touch test deviate from the above list, suspect a restriction in the line or the component is abnormal. confirm this with a pressure test.
and check all the fuses