Very new to this, please help. Need help with the outside AC unit that will not turn on for some reason. It is a Carrier residential product. I have tracked down the problem to it because the thermostat is turning the system on as a whole, the air is blowing from the furnace like it should be. The motor in the outside unit is making a buzzing noise and is heating up tremendously. My first immature guess is that its the motor that might need to be changed. But are there any other things that I can check before calling an HVAC guy and spending hundreds for something I can maybe do myself. If I have to change the motor it's pretty self explanatory I presume?