Volvo AC does not blow cold
 

I just purchased a great 1991 Volvo wagon from a friend and drove it 10 hours to my home. It drove like a dream. I am afraid, though, that I taxed the AC because it no longer blows cold. It was blowing cold as I first drove the car - for about 3 hours - and then the air started getting warmer. It does not blow hot air, but the air is not cold. About 10 years ago my friends replaced the AC system, so it no longer has the original freon type system. Any thoughts on what I can do before taking it to a mechanic or dealer? Someone told me the AC system might have to be recharged. Is this something that needs to be done periodically?
Appreciative of your help.

This should be in the 850 sub-forum, but since im bored here Is my opinion..

It only needs to be recharged Often if you have a leak. Which sounds like may be your problem.

First things first you will want to see if the compressor cycles quickly (turns on-off-on-off),If so You might be low on Freon.
If the compressor does not kick on at all you will need to check to see if it has power.

I would bring it to a shop and get your pressure level readings read.
My advice would be to have them check your settings and if it is low, have them vacuum and recharge the system and inject it with dye so they can pin-point where you are leaking. Most Places at least here in miami will do this for anywhere from $60 to $100.

It could be anything from a valve-core, to the dreaded evaporator (not too expensive parts wise of a job but it is time consuming) and anything inbetween.

91 Volvo wagon? 245, 745 or 945 but certainly not the non-existent 850. Regardless, the advice stands. From your post, I would presume you know little about a/c. Take it to the shop and have a pro check it out. You'll save money in the long run.

LOL... I thought that said 94... WOW i need contacts..