My ac went out on my 98 cadi deville a few month ago. It just tells us low refridge. we tried to put some more in and the gage to fill it up says it is still full. but since then my econ/vent; heater; rear window defrost, front defrost, driver seat adjuster, driver rear view mirror heated thing don't work what could be wrong? & how can i fix it?

It sounds like you have either a low pressure cutoff switch that is faulty or connection at the switch/wiring. The computer will only see the fault while it is operating and it will only set the code after 2 consective faults. Make sure you have the system checked by a professional to make sure pressures are correct in the system first.

short compressor, run wire from battery and ground

add R134a freon and use a fill hose with a gage and keep in safe range. Keep can upright to fill system as a gas. Inverting will send a flood of liquid freon in - not good.
Can you hear the a/c clutch engage and disengage a few times/minute?

there are two lines high and low side you put the freon on the low side also check the back of the freon can

You can put a scanner on the car and read the code if any is set. Then repair the code.

cheep gas you may have 2 put some octane booster a few.. fuel filter . catalytic converter..listen 2 the exhaust

It seems that you have a leak, best bet is to bring it to someone with a set of gages to check the pressures while the ac system is operating. The high side should be about 150-200 psi and low side between 30-40psi with those numbers you should be running very cool. If its not that high then you most probably have a leak in the system most probably at one of the recently replaced parts or a new place, fill the system with a uv dye and recharge. drive for a week or two and check with a uv light.

the sensor that detects low freon went bad and your compresor is not turning on try replacing that sendor

Have your a/c system charged and tested for leaks.

Check the filter to make sure it the right one and on tight. Do not drive without oil. Engine will seize-up.