Car states freon low cut off a/c, how do I add freon. I am a female and do not know where to put freon in car or how.

Well, it can be several things. There are high and low pressure cut-off switches. The A/C freon pressure is directly linked to outside air (under hood) temperatures. So if you are at the extreme in either direction, the pressure switches may cut-off.

This is not to eliminate that a pressure switch can be bad. They can usually be replaced without losing Freon. On the other hand, if the Freon system was not sealed, moisture may be icing up and blocking the lines. This can be really bad if the ice forms in the compressor.

As part of a A/C repair a vacuum pump is attached to the Freon lines before refilling. The vacuum pump is run for some time until a vacuum is created and this will draw all moisture out. This will eliminate ice. Then you add the correct compressor oil and quantity and put in the correct amount of Freon. The best amount is usually the makers recommended fill. Maximum cooling happens when the compressor runs the longest and is a balance between the high and low cut-out points.

Need make and model. Do you know if the compressor is running?

If we are talking about a pressure switch, it usually is the low pressure cut-off switch. Before messing with this switch, verify what your Freon pressure is.
If the pressure is low, the low pressure switch may be fine and you need to add Freon and find out why the Freon escaped.
If you have high pressure, there is a second switch which cuts power to the compressor. Too much Freon will activate this switch.
Tip: You have both a high and low pressure switch. The proper amount of Freon will center the pressure and keep the compressor running more consistently.
Either pressure switch unscrews from the fitting and with a minimum of pressure can be removed from the lines and replaced. The housing should have shapes for wrenches.

Not sure what the question is - but you have to have the compressor running to add freon.
Most times if it is low you have to jumper the low pressure switch to make the compressor run long enough to add freon.
Under normal conditions, low pressure should be 35-45psi and high side should be 200-300psi with the compressor and cooling fan running.

Sounds like you might have a leak. If you charge the system and works for a time ,(hour, week, year) and then quits it sounds like perhaps the freon is leaking out somewhere. Freon does not ever get converted to air. Freon is in several states of existance while it is in your system. It is a high presure liquid, high presure gas, low presure liquid, and a low presure gas, but it is still always freon.
The valve your friend is talking about is called an expansion valve. What it does is to take the high presure "liquid" freon and allows it to pass into a low presure zone called an evaporator at a regulated rate. When you take freon at a liquid state high presure condition and expose it to a low presure environment it "evaporates" ( thus the name evaporator) and it gets very cold when it does this. This is where the cold air you feel coming out of the vents is made.
But the freon is in an enclosed system. By this, I mean it is never exposed to air, moisure (water), or anything else. I goes through all of these changes while inside this enclosed system.
Therefore, if the enclosed system is good then the amount of freon inside it will not change. If the amount of freon doesn't change then adding more will only make things worse.
I would suggest having the system checked with a hologen leak detector and/or system dye to find the leaks. Remember, if you have to add freon, then the freon that was there before must have escaped from somewhere.
Find a reputable shop to check the system for leaks. If it is leaking bad enough to run low in a hour it should be an easy to find leak.

your vehicle came with R12 u can not purchase it , well depends on your STATE. but you will need to retro fit for R134A unless there is R12 still available at your area.

there are 2 locations a high side and low side most people use the low side connection to add freon.

Try to add freon,it is most likely low,and needs the recharge,also,if it leaked freon,it leaked oil,so put some oil in it also,If this was helpful,please rate,thank you.

Add freon if not done yet, disconnect battery for 5mim, should reset, if it don't reset after disconnecting battery, your low pressure switch's are bad, that happens about 50% of the time when freon get's low. the low switch's are located on a very thin a/c line that run's along the top of the fire wall, there will be two about 12" to 18" apart, on the same a/c line, recover freon before removing switch's, install new one's evac a/c system and recharge with 2lbs of freon, hope this was very helpful.

If there is 12 volts at the compressor,then the coil on the clutch is bad.Most of the time,compressor with coil/clutch,is cheaper to purchase than just the clutch.I hope this helps you.

Adding freon will not correct the problem. If you need to add freon, you have a leak, and you have moisture in the system, the leak should be located, mositure removed, then freon added. But to answer your question. Open the hood on, the left side you will see a round object called a dryer, you will see two pipes coming from it, one at the top and one at the bottom. The smaller is the high side, the larger is the low side. Obtain a can of freon either R-22 or 134a with an adapter for installing the freon. Turn the engine on, turn the AC to high. Add the freon to the ac using the low side.