Alternator in Massachusetts

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.

Coastal air adds to what the roads are already doing.

The climate, in a number

Boston's record winter put 110 inches of snow on the ground across the season. Every one of those days is a day the cooling fan, the air conditioning clutch and the blower are all drawing at once, and the alternator is what carries them.

Does this state inspect your car

Every vehicle driven on the roads here has to pass an annual safety inspection, which covers brakes, exhaust, steering and suspension, tyres and wheels, lights and seat belts. A charging warning light is a fault an inspector sees from the driver's seat, before anybody opens the bonnet.

Salt, on top of everything

The winter is long and the salting is heavy, so every failure above happens to a car whose underside is also corroding. The practical consequence is the salt-belt buying rule: in this climate the removal is the expensive half of a job, so the complete assembly usually beats the component.

A loaded caliper rather than a rebuild kit for one that is already pitted. A complete hub rather than a bearing pressed into a corroded knuckle. A complete strut rather than a bare damper on a lower bolt that has bonded into its sleeve.

What else Massachusetts does to a car

Heavy road salt on the oldest street layout in the country.

Rotary junctions and tight parallel parking work the steering and suspension constantly at low speed.

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 Massachusetts, including Boston, Worcester, Springfield and Cambridge.