Alternator in Wyoming

Winter is a sustained electrical load

Short Wyoming winter journeys ask the charging system for everything at once: headlights against a dark afternoon, the blower at full, a heated rear screen, heated seats, and a battery that has just given up a large amount of current to a cold start.

An alternator that is merely tired copes in July and cannot keep up in January. The symptom is a battery that goes flat repeatedly and tests fine each time it is charged — the battery is not the fault, it is the thing reporting one.

The highest mean elevation of any state, with I-80 wind and closures on top of the cold.

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.

Extreme wind loading and gravel beyond the interstate.

The climate, in a number

On the 1991 to 2020 normals, winter minimum temperatures across the state's weather stations sit mostly between 5°F and 18°F. 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.

What goes on the roads in winter

When a storm hits, crews spread a salt and sand mixture for traction and plough behind it, with 374 snow ploughs on the road. What is spread on the road reaches the alternator through the same wheel-arch opening that cools it, and a case packed with salted grit runs hotter than one that is clean.

Why this one here

A charging fault a hundred miles from anywhere is a tow, and the altitude and temperature range here are hard on a regulator.

Cold, and salt on the passes

Winters are long and severe. At twenty or thirty below a battery delivers a fraction of its rated current while the oil the starter must turn is at its thickest.

The damage that kills a battery happens in summer heat and cold only reveals it — which is why replacing on age, before winter, beats replacing on failure at a rest area on I-80.

What else Wyoming does to a car

Real grades at altitude.

Long empty highways between services.

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 Wyoming, including Cheyenne, Casper, Laramie and Gillette.