My thermostat will not cut off when it gets down to the temp. I received an answer stating that the contactor may be stuck. How do I find out if it is stuck and if it is can I fix it or should I buy a new thermostat?

If the blower shuts off but the compressor keeps running it sounds like a contactor and not a thermostat problem.

When you turn off your thermostat does the indoor and outdoor unit continue to run or is it just the outside unit? If the indoor unit turns off and the outdoor does it is very possible that it is your contactor. Instead of trying to unstick the contactor it would be best to replace it, they are very cheap depending where you buy it, under $25 dollars. If you know about electricity and how to work with it you could do the job yourself, if you don't know how I would surely let a tech do it for you. Whole job probably less then $100.00.