91LXStang2727

How does the alternator get power?

duslep

I can't say that i know for sure, but it is belt driven just as the a/c and smog pump are.
and by the belt turning the alternator pulley it builds up power. But thats just my understanding.

r.barn

alternator makes power.

it's an electric motor in reverse, you spin it with the engine
and makes power instead of using it.

randy78045

Alternator MAKES power and in fact powers the engine (not the battery) and is run by the belt...

90GTRagtop

What they said. But an automotive alternator does require an external voltage to excite the field to enable it to make power. After it has started, it could get power from itself to do this, but it needs a start. Therefore, without a battery, it won't charge. The exception to this is the one wire variation of a GM alternator. It uses a capcitor to store an initial excitation charge. Sometimes, if it sets for a long time, the capacitor can discharge and you'll need to charge it back up to get the alternator to work again.