I need help with a buzzing sound in my air conditioner.

The fan motor is thermally protected the motor seems to be cutting out on the overload replace the fan motor

You could do it with a wireless thermostat and just have 2 thermostats right next to each other with a sensor for the other one. I think that's your best option, look into a wireless thermostat.

Bad thermostat, improper wiring or bad circuit board in furnace. Turn off the disconnect outside.

The attic fan is not a part of your a/c system, and you should not run it while you are running the a/c. If you are currently using the attic fan, it is possible that someone wired it so that the a/c won't turn on while the attic fan is on. Otherwise if the thermostat is set below room temp, and says it is calling for cool, then the problem is most likely coming from an issue at the outside unit itself. Make sure to check your fuses, at the fuse panel and outside breaker. Hope this helps

FYI.. the only part of the system that might use batteries is the thermostat.

The buzzing noise is your contactor drawing in from your thermostat. The fan part of your unit is on a different circuit from your outside A\C unit. Your thermostat is the conductor of the orchestra tying ths units together. It may well be that your A\C circuit breaker has tripped, if it has there is a reason for it's tripping. Resetting the breaker by turning it off then on may get your unit running, but a technician needs to ascertain why it tripped. Or it could be a bad contact switch inside the outside unit not letting enough electricity through the switch. More than likely the first issue. Good Luck

Check the start capacitor. You may be able to see visual deformaty, otherwise, use a meter. The buzzing is most likely the contactors closing which uses a seperate 24v supply..

If you have a Gas furnace in the Attic then the answer is yes. The outside condenser will not run if in fact you have a gas furnace.

check your wiring on your t-stat maybe yellow and red touching, how old this house

Things that are not broken: The big relay that powers the compressor often hums or buzzes when the unit is running. Several brands of heat pumps keep their reversing valve "on" any time the thermostat is set for "cool". They buzz, too.

If something really is loose, the only way to fix it is to look at the machine and take off panels until you find what is buzzing.

Even when the power is off at the unit outside the thermostat will supply power to the contactor of the outside unit. This may give a hum or buzz as you stated. If when the power is on to the outside unit the fan tries to start but only hums the motor may be bad. Does the compressor start and run?