Air conditioner

If it was a locked up compressor did you also flush all of the system to remove any possible debris from the failure? If not then that would be step one. Replace the drier as well. Did you drain the oil out of the replacement compressor? If not you need to do that as well. Then pull a vacuum on the system for at least 30 minutes to be sure you remove any moisture from the system, then verify it holds that vacuum for at least 20 minutes or longer. Then once you are sure the system is good you recharge with the proper amount of oil first, then charge the system by weight (amount will be on a sticker on the fan shroud or radiator support) Being an R-12 system you may have difficulty finding R-12 to charge it with and r-134A doesn't work real well in those without some other changes.