Or the limit itself could be bad. However the buzzing you're hearing may be the motor attempting to run, which would lead me to believe the problem would be the motor or the capacitor. Easiest way to check is to turn on the fan, carefully reach back and feel if the fan is vibrating and getting hot. You can attempt to spin the motor (again be careful), if it starts & runs normally after you kick start it, the capacitor is probably the cause.Sure can. Limits trip because the unit has gotten too hot due to lack of air flow. That could be from a dirty filter,a dirty evap coil, a bad capacitor on a blower motor, a bad motor or a bad control board not sending voltage to the motor.