So i am trying to figure out what is wrong with the A/C. I have never worked on an A/C system before, but i do have some of the components needed to work on it. My friend has a vacuum system i can use and i have some R12 as well. I guess i am trying to figure out what i should test before putting new R12 into the system to make sure all the components are working (before i waste the r12)?

I know i should also add some oil to the compressor, but was wondering if there is a good way to test the compressor, condenser, evaporator etc...?

Thanks!