1996 volvo 850 a/c blowing hot air
 

took car to mechanic who specializes in foreign cars. he could not fix it since he did not have codes. where do we get codes? who is the best and cheapest authorized volvo dealer in boston area?

If the A/C is not working, take it to someone that works on A/C systems. Nothing special about the Volvo A/C system. It is likely low on freon but again, let a pro take care of it.