For a properly operating CC system simply set the temp dial to about 25 and leave it there or adjust it a few degrees one way or the other for your own comfort. DON'T set it on Max or Min. Let the system automatically adjust temp for you.

Then press the button that has a solid white up arrow and a solid white down arrow. Then press the fan button that says auto.

If it is working correctly that's all you need to do. If it is blowing real HEAT all the time, the problem is likely to be the monovalve that has four screws in the top and it's near the battery. This is a common problem.

Another common problem is that the hose on the climate control temp sensor disintegrates and disappears. This is that little grill in the upper center of the dash. Remove the glove box and look behind it. There should be a hose that goes across to the left of the glove box to that sensor below the little grill. Go to home depot and get 3/4" foam hose that is used to insulate pipes in the winter time. Cut a section the right length and put it in place.

These are the two common failures of the climate control system. This does not take into account the refrigeration system. If it has freon, and everything above is set and checked the compressor should kick in. If it doesn't it is probably low on refrigerant and will have to be seen to.

Good luck,