My AC doesnt put out cold air on my 85 Westy.  It was that way when I
bought it.  It has R12 in it.  A local shop tells me that what they do is
evacuate the system and put in R134 and if the system is ok it will work.
 I had always heard you have to get into the system and modify it for R134.
 This local shop has a lot of experience and if its that simple I'd rather
go that way.

Jim
85 Westy