Photo by Killian Eon from Pexels

To understand your motorcycle’s electrical system, you must know how electricity works. 

And the best place to start is to learn about voltage, current, and resistance.

While this blog post won’t teach you enough to become a certified electrician, you will discover:

  • The definition of Voltage, current, and resistance
  • Common reasons why you need to measure Voltage, current, and resistance

What is Electrical Voltage?

Voltage is the difference in electrical charge between two points.

Think of voltage as a force that pushes the electricity around.

To put this into perspective, take a look at the terminals on your motorcycle’s battery.

What if the negative terminal and the positive terminals both contain the exact amount of electrical charge?

Then there’s no difference – the voltage would be 0.

No difference means there’s no force to push electricity between the two terminals.

But, what if the positive terminal contains more electricity than the negative terminal?

Then, there’s an electrical charge difference, and the voltage increases.

The more difference, the higher the voltage will be.

That’s why you always measure voltage between two points (such as between the positive and negative terminals of a motorcycle’s battery).

What is electrical voltage measured in?

You measure voltage in “Volts,” which is usually indicated by the letter “V.

Why do you measure electrical voltage?

To see how much voltage is getting to or coming out from an electrical component, such as:

  • A headlight
  • An ABS sensor
  • The battery

What Is Electrical Current?

Current refers to the flow of electricity. Specifically how fast the electrons inside the electric conductor flow.

The faster the electrons move, the higher the electrical current will be.

What is electrical current measured in?

When you measure current, you measure in “Ampere,” (or “Amps” for short) indicated by the letter “A.” 

Unlike voltage, you can measure current at a single point. But how is that possible?

That’s because where there’s an electrical current, there’s a small magnetic field. 

Because of this magnetic field, you can measure current with a tool known as a “current clamp.”

Why do you measure current?

Electrical current is a key player in any electronic circuit. If there’s no or too little current, all components that use power (known as “actuators”) from that circuit either won’t work or will perform poorly.

What is Electrical Resistance?

Resistance is something that restricts or reduces the current flow in the circuit. The higher the resistance, the more the current is reduced.

How is resistance measured?

 Ohms is the unit of measurement for resistance, indicated by the character “Ω.”

When you measure resistance, the current must flow through the circuit you want to measure. If it flows through a different circuit, you might get an inaccurate reading.

The easiest way to prevent this is to completely disconnect the circuit. That way, you can ensure you’ll get an accurate reading.

It’s also good to know that resistance changes with the temperature. 

If you measure the resistance in a light bulb, the resistance will be much higher when the light bulb is warm.

Why do you measure resistance?

Sometimes, a sensor might not work correctly. Often, this is because of too much resistance. 

The correct amount of resistance for the sensor is in your owner’s manual. By comparing that resistance with the resistance you get, you can determine if the sensor’s working properly.

What is Wattage?

In the context of electricity, “Wattage” is the amount of work that is performed during a certain period of time. 

In context, an electrical component such as the headlight uses a wattage between 60-100 W.

What is wattage measured in?

You measure power in Watts (after James Watt, inventor of the steam engine), indicated by the letter “W.”

Electric two-wheelers measure engine power in kilowatts (kW), rather than cubic centimeters.