Cadillac Repair: 94 Eldorado A/C, adding freon

Question
I need to the the ac going and don't know what to do. What do I need to do to get the freon into the tank?  I guess the compressor isn't sucking the freon.  How do I get the compressor going?

Answer
Hi Joy,

    Working with the a/c system can be a dangerous job if you don't know what you are doing. If freon starts to spray from a can that was not installed to the hose or car propperly it can cause a freezer burn with-in a matter of seconds if it comes in contact with eyes or skin. Thats why saftey glasses and gloves need to be worn.

    Not knowing your situation and why the compressor doesn't turn on just adding freon might not be safe. For example you could have the correct amount in the system but a low or high side temperature sensor could be defective and not allowing the compressor to turn on. I had that happen yesterday with a truck. The high side sensor was bad and told the computor that the high side was like 500psi so it set a code and wouldn't allow the compressor to turn on. So hooking up gauges to the low and high side valves are a must. Also check for codes. You might have a current code that is keeping the compressor off and fixing that problem and clearing any a/c codes that are stored will get the comp. working again provided there is at least 3/4 lb of froen in the system.

    Freon can be installed in eithor side but if the compressor is running through the low side only or you can blow up the can and cause serious injuries.

    If the freon all leaked out or you had to replace a part, then the system needs to be put into a vacuum for at least 15 minuits and up to 1 hour depending on your vacuum pump because the moisture needs to be boiled out. Otherwise things rust internally and the compressor will be damaged.

    So what I would really like to see you do is take the car to your mechanic and have them do the repair. You might be able to watch them do the testing from a safe distance and then you will know what to do for the next time or maybe it is something you are glad that you didn't attempt. Otherwise go to the library and get a shop manual and read up on the propper way to test and install freon. A good shop manual on-line is alldata.com   They are the same company that your mechanic might have and it will tell you how to check and clear codes, that the code is and how to test it, and then how freon gets into the system and what tools are used. Bill