Bad bearings in an alternator would make a grinding or roaring sound. If a Diode Plate is failing you might hear a buzzing sound in the radio that changes pitch with the speed of the engine.
What kind of noise WOULD a cat make?
Its kind of a grinding screeching metal on metal noise.
start by checkn the Battery,I would put my lights on to see if they are workn, if they are not then it is your battery. If not could be your alternator.
What kind alternator is? Is Bosh or different kind?
Don't ignore that kind of sound. Find out what is causing it and replace or repair the faulty part. A "grinding noise" can be caused by an alternator, water pump, idler pulley, heater fan motor, air pump or any of a long list of components, many of which can cause some serious problems if they seize or come apart.
If it's a type of clunking noise, check your gearbox. If it's some kind of rattling, check your hubcaps.
intermodulation noise
What kind of vehicle do you have?
dc
A noise is that kind of sound which feels unpleasant to your ears.
a noise why don't you hit it and then you will find out :)
It makes AC ( alternating current ) . That's why it's called an alternator. A DC generator would usually be called a dynamo.