How An Alternator Works in a Truck

Many people know the battery offers power to the windshield wipers, headlights, or even radio. But is that really the case? The power from the battery is necessary only when you start your truck and when the engine is off. It is the alternator that does all this. In this guide, we will go through the steps to learn how an alternator works in a truck.

What is an Alternator?

Alternator performs the role of converting mechanical energy into AC electrical energy. The alternator works similarly to the generator. The slight difference is that a generator converts mechanical energy into either AC or DC electrical energy. The converted energy powers other parts of the truck, such as the wipers, headlights, and even charging the battery.

Components of an Alternator

The components of an alternator give your truck the correct amount of power. Let us look at the parts of an alternator and what they do.

Rotor and Stator

Inside the stator is a rotor surrounded by a magnet with conductive copper wiring. The rotor and stator generate electricity by moving the magnet over the wiring. The two are the main components that produce power in a vehicle.

Voltage Regulator

From the names, it oversees the power the alternator makes and delivers to your truck and the battery.

Diode Rectifier

Converts the power from the alternator into a form that the battery can use and store.

Cooling Fan

Cools the alternator, which produces a lot of heat when functioning. It has rotating fun and aluminum casing that dispenses heat from it to the surrounding. 

How an Alternator Works

An alternator does the work of producing electricity and charging the battery of your truck. How an alternator performs, the above two roles will let us know how it works.

How an Alternator Generates Electricity

The engine is the primary source of electricity. An alternator has mounting types. In old engines, a pulley moves from the crankshaft to the alternator. In new engines, the alternator has a serpentine belt that connects it to the crankshaft. The mechanical energy resulting from the belt movement is what spins the rotor at a very high speed. 

The spinning of the rotor produces electricity. The magnets create a magnetic field as they pass over the copper wiring in the stator. The magnetic field generates the voltage which the stator captures. The power from the stator goes to the voltage regulator, which transfers it to other parts of the truck. 

How An Alternator Charges a Truck’s Battery

The electricity flows in different ways, but the battery only receives current in one way or direct current. The current intended-to-go battery first moves to the diode, which converts to DC before moving to the voltage regulator. The alternators generate the alternating current, which can flow reverse. After the conversion, the current charges the battery or gets stored. 


The alternator does the primary role of converting mechanical energy into electric energy. It gets the mechanical energy from the engine as it functions. Upon successful conversion, the electric energy will help power your radio and wipers and charge your battery. The alternator has parts which does the energy conversion.

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