I know that if the alternator takes a crap the charging light will come on, but what about the voltage regulator?

If it goes bad and allows the voltage to go up will the light come on then?

if the alt does not put out any voltage, whether bad alt or bad regulator, alt light will come on. if alt puts out excess voltage due to bad regulator, light will not come on. but when my regulator crapped, it was neither high nor low, but all over the place causing gauges to go haywire.