A/C issue

This is the GL wagon. my A/C works great when it works.
in order to get the A/C to work i have to set the selector to defrost wait a minute or three then switch to A/C and i will get nice cold air. but, then sometimes it will just go to warm air and i have to play with the controls to get the right sequence to start over again. what needs replacing? interestingly i have a similar problem with the cruise control, but it works once a day! when i start out in the morning the cruise works! until i hit the brakes then it will no longer work (until the next morning). the the same thing works fine once a day.