Quote Originally Posted by wickedintent79 View Post
Theres a high side and a low side high being red and blue being low im pretty sure you add into the low side and turn the ac system on we did it on a few gm cars in school but we used machines for it all. if using one of the auto zone kits im pretty sure it will onl;y hook up to on side not the other
yep, on the 134a car the high and low side hook ups are different sizes. Alot of cars have red and blue caps on the hook ups. R12 cars are a different story, they weren't dummy proof and you had to be more careful with the connectors. A/C systems work basically the same in a house as they do on a car. I pretty sure your right David, you have to charge the system on the low side with the refridgerent in liquid form. It has to be a gas to be on the high side because a liquid won't compress and you will ruin your ac compressor. Hope this helps. Alot of car stuff is hard to explain over the computer.