i had it recharged and it blew really cold for a week or so and then progressively went back to blowing hot air. any ideas on where i should start?

 

Was the new refrigerant lost from a leak?

 

i would assume so.

 

Find leak, fix leak, recharge.

 

Did you test it and see if it would hold a vacuum for about 30 mins or so? If not do that before you waste more freon. If it holds it for a good 30 mins or longer than its a compressor leak. The seal inside the compressor go bad just like everything else with age. I had the same problem and when i tested it, it would hold a vacuum fine but would slowly discharge over use. It was a bad seal in the compressor, i couldn't find a kit for it to put new seals i wound up having to get a new compressor for it

 

I just dealt with my AC in my EG. I had multiple leaks, one was from the evaporator, another was from the O ring in the low side line & the final was was in the condensor. I would HIGHLY reccomend using a UV light with dye

hopefully this helps.

 

if you find no leaks like stated above, its your compressor seal. Sometimes you can put the seal stuff( cant remember the exact name) that you can pick up at the parts store for around $25 to help seal small leaks. Small being the key word.

 

check the heater core thing in the engine bay that stops the flow of coolant into the heater core.
could be stuck open