If your talking about the A/C on the vee dub get your eye balls on the cooling fans. If BOTH fans don't kick on with AC engaged you've got either a bad fan motor or bad fan control module. One will prevent the AC from engaging one will cause excessive pressures at idle, which over time creates problems in itself, IE off gassing. The blend doors also become problematic at this age. It's a Very simple straight forward system. I can get into it more in depth when you dig into it, if you'd like.