A/C compressor will not engage

Ice cold in the morning and it just stopped working. I put gages on it and there is no leak, it is still full pressure. I checked fues in cab and on top of battery and they are fine (3 in cab, 3-30 amps on top and one forty). I push in the ac switch and both fans come on as they are suppost to. Compressor clutch is not locked up. I was wondering if it might be the fan control module, I know that tells the compressor to come on, but if that was bad would the fans still come on with ac button on in
side of cab? My coolant was a little low the day it happened my light came on so I topped it off. When I do push in the ac button the car will idle up then down over and over till I turn ac button off. Also I was wondering if my fan control module has a fuse on it somewhere I know some of them have a 20amp and 7.5 amp. I can't see mine with it being under the battery. Thanks for any help! Ben :)