How do I go about getting the old A/C system working again? Do I just have it charged with the new R134a or do I have to get a retrofit kit from the dealer?

 

You need to use a retrofit kit, Here you can pick em up at any auto parts store for like 20 bucks, then you need the R134a to fill it up with. They come with very detailed instructions asfor me; I pulled mine all out (compressor, evap core, hoses). as it was dead weight.

 

And while we're on the subject, how would the home mechanic discharge an A/C system without hurting himself? I need to do so to rip the motor out of my parts car.

 

I know they make a tool that can depressurize the freon and has a lil containter (like an air tank) to hold it in after it takes it out.

In theory, bad for the environment, but in theory you could just depressurize it the way you would a tire or fuel rail...

One other note, if the system doesnt work there is a good chance there is little or no freon left in it.

 

Good to know that. Being as it's a '92, I'm assuming there's little or none left in it.

 

Also, some places still sell whatever R12 they never sold to begin with (extra stock), its not made any more so its costly.

ONE local shop still carries some, at a wooping $99/lb for it (thats US dollars)

 

I just take mine to a shop and have them evaculate the system I found a shop that does it for $20 us dollars Which they vacumm it out then leak test it make sure you have it vacummed out this will remove any foriegn objects that may be in the system then after that add 1 can of ester oil then take the cans of freon put them in hot water(not boiling) but this will increase the pressure when you put the fluid in and make sure you have the a/c on cold fan low speed engine running. Turn the can upside down. Then puncture the hole in the can.I have done these steps many times it works great the chryslers have a oriface tube in there a/c systems which i think get colder then the chevy style a/c systems and are more likely to work better then chevys tend to but i have had good luck with both types of systems,one other note if your pressure is too high sometimes it is because the tube which is in the evaporator can gets plugged and you may need another one i have often seen this problem.It is easy to replace this tube just take the big hose off the evaporator hose and pull it out do this before you have it vacuumed out and check for dirt in the tube. r134a is more acidic then r12 a lot of times it will eat up the evaporater pretty quick and cause it to leak some sytems won't effect it, some will.I hope this will help you out.