The next time your AC is having problems, try these DIY troubleshooting tips:
Look for a dirty air filter: If your air conditioner isn't getting enough airflow, it can eventually fail completely and result in a whole host of other issues.
Verify the thermostat's settings: Make sure the thermostat is set to “cool” rather than “heat”. Also, be sure the fan is on “auto” and not “on”
Check the circuit breakers: Examine any circuit breakers that aren't in the ON position at the main electrical panel in your home. Look specifically for a circuit breaker marked "air conditioner" or "AC" if your circuit breakers are clearly labeled.
Look over your outdoor unit:  while you're outside use a hose on a gentle setting to remove any dirt you see on the exterior of the appliance.
Check each air vent: Make sure all supply vents, including those in unused rooms, are open and unblocked as you walk through your house.