Ford Repair: Mercury Tracer air conditioning problem, mercury tracer, 1999 mercury tracer

Question
I have a 1999 Mercury Tracer sedan with a 2.0 liter engine, my wife drove it yesterday and the air worked perfectly and when she got in it today she turned it on and it blows warm air. I am a former mechanic so i took a look at it and the compressor wasn't cycling on and off so I jumped the cycling switch on the low side and still nothing. I wouldn't think that it would be out of coolant since it cooled to the point of making them cold yesterday in 97 degree weather but not sure since I don't have any gages. I also checked if the electric fan came on with the air switched on and it does. I checked the 2 wire switch on the compressor and it isn't getting 12 volts. If you have any ideas i would appreciate it.

Answer
check fuses first-some vehicle use the same fuse for blower and compressor some are seperate-this is a 99 tracer so jumping low pressure switch may not work if  you have a bad relay control box i would verify that it has freon first if you don't have guages find someone who does and don't take for granted it has freon in it. look around condensor to make sure a piece of debris hasn't came up off of the road and punctured it. good luck.