My '90 740's A/C wasn't blowing cold air when I got her last year. I browsed through the FAQ and saw some guidance, but I'm unclear as to how the system works, where the components are and what is that failed.

I hear lots of people talking about R12 systems (which I'm assuming I have) and how they've painfully and expensively converted over to R134 w/ kits and all. And yet at the local Walmart, etc I see generic R134 kits that look rather affordable. I plan on junking the car in a year or two, so i'd like something affordable that could possibly work for at least that span of time.