motor buzzes loudly, won’t start. lights dim when doing so. motor and transmission turn freely
Check and see if something is caught in the pump.
Remove the belt, see if pump rotates freely.
If it does, then pump is ok.
This could be your motor or motor switch. If the motor does not get the proper voltage, then it can cause it to hum. Humming can also be caused by a failed motor windings…
If you can safely check for voltage yourself, check to see if motor is getting proper voltage… if so, then check wiring and connections, if all good, then it is most likely your motor or motor switch.
You can check resistance of motor windings to check motor… check tech manual specs for proper readings.
good luck