Alternator in the United States

The connections corrode before the machine does

Damp air works on the exposed side of an alternator: the terminal stud, the plug on the regulator, and the earth strap between engine and body. A resistance in any of those looks exactly like a failing alternator on a meter at the battery, and is a fraction of the price to fix.

Check the charging voltage at the alternator's own output and then at the battery. A meaningful difference between the two is a connection, not a machine.

An alternator breathes whatever the road throws up

The case is ventilated, because the machine has to shed its own heat. On unpaved roads that means it is drawing dust through itself continuously, and the dust ends up on the slip rings and in the bearings.

A whine that rises with engine speed rather than road speed is a bearing. It is worth catching, because a seized alternator bearing does not stop at the alternator — it takes the belt, and everything the belt drives goes with it.

What else the United States does to a car

Which of these matters depends entirely on where the car actually lives, which is why the state pages are the useful ones.

What we hold, and what it costs

5 options from Bosch, Cardone, Denso, Remy and Valeo, from $239.99 to $309.99. Prices are firm — where we have no price we publish none.

We are a reseller rather than a manufacturer: we source the part, check it over and sell it, and we confirm it against your year, make, model and engine before it ships rather than asserting a fit on the page. We ship anywhere in the United States.