great new 156 jtd,no air con/vdc failure

i've just bought a lovely 156 jtd (my first alfa)but i have a couple of problems.first being the air con(totally forgot to check it) it doesn't blow cold so i took it to be regassed,the guy hooked it up and told me it was fully gassed already.he fiddled around for a bit then told me the compressor works but there was no power supply to it,after checking a few fuses he said i would have to go to a proper auto electrician.i thanked him and went on my way.when i got home i found it was a blown fuse,so now the compressor works but still blows warm. any answers to my long winded question would be much appreciated i know u guys are brilliant at helping out people in distress!
my second problem started 3 days after i bought it,i started the car and it came up with vdc failure,is this going to be expensive and will i have to go and get it diagnosed.
many thanks to everyone who answers.

air con prob: can you hear the compressor kick in and out when you turn it on?
A sensor could be down on the system, you need to take it to an A/C company that can look at and diagnose the entire sytem.

VDC, could be a sign that the battery is on its way out. I have the same problem, I also have 2 spare batteries, just too lazy yo change it!
Thats if it comes on just after starting then goes out a few mins later. usually OK if you start it and keep the revs above 1,000rpm, alternator provides enough voltage then