Alternator in Mississippi

Heat is what ends an alternator here

An alternator is an electrical machine bolted to the hottest part of the car, and its regulator and rectifier diodes are semiconductors with a temperature limit. Mississippi runs them above their comfortable range for months at a time, and under-bonnet temperature is always well above ambient — a ninety-degree afternoon is a great deal more than ninety degrees at the back of the case.

What that produces is not a dramatic failure. It is a regulator that drifts, so the charging voltage wanders, and diodes that leak, so the output ripples. The battery then lives undercharged and gets blamed first.

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.

Gulf humidity and Delta flooding.

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.

Poor rural road surfaces over long rural distances — the two together are what break suspension components.

The climate, in a number

Statewide annual precipitation averages 55.9 inches, from 50 inches in the north to about 65 along the coast. 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

Mississippi inspected vehicles from 1961 until 2015, which makes it the most recent state in the country to stop. Nothing will flag a failing alternator for you here: the warning light comes on once the regulator has already given up, and by then the battery has been taking the punishment for weeks.

Why this one here

A long way from anywhere is the wrong place to discover the charging system was marginal.

Humidity and heat

Long, hot, very humid summers. The air conditioning compressor spends most of its work condensing moisture out of the air rather than lowering its temperature, which makes the duty cycle far longer than the temperature alone suggests.

Humidity is also the corrosion mechanism here, since there is no road salt at all. It works on connectors, grounds and aluminium rather than on structure. A fault that behaves differently in the wet is a connector, not a module.

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 Mississippi, including Jackson, Gulfport, Southaven and Hattiesburg.