A/C question

My air conditioning worked one day and when i started the jimmy up the next morning the air conditioning did not work. The compressor will not engage. Is there something that I can check, ie: switches? The fuse is fine. Does a compressor work fine one day and then not the next when it goes out? Can i jump a line somewhere to see if it will engage and possibly be something else?
Thanks

There are two places. 1 is on the pasenger side of the truck just above the front tire. You can pull the plug off the siver cylinder and jump across it. This is your freon pressure switch if jumping this causes the compressor to kick in it means you are low on freon. The other is the 2 wire plug that plugs directly to the back of the compressor.