Just bought a 94 and ac is out. I can't find any info on compressor or data plate under hood about what kind of freon was in this system. Does anybody know? If it is r12 I was planning on changing it to r134, anybody had any luck with this before? Thanks for your help in advance.

 

The Schrader valve fitting where refrigerant is added to the vehicle is completely different for R12 & R134. The fitting will tell whether it's been converted or not. Conversion to R134 works fine.

 

I had a 1994 Suburban once, it was R134, clearly stated with stickers in the engine compartment.

 

Thanks for replies,,,after looking harder,,, cleaned off some grime/dirt and saw r134 label.