EEPROM a type of non-volatile memory used in control modules (ECUs/ECMs) to store data even when the vehicle’s battery is disconnected. current (I) The flow of electrons through a conductor, measured in amperes (amps). watt (W) Unit of electrical power; Power = Voltage × Current. alternator Generates electrical current while the engine runs; charges the battery. continuity A complete path with no open circuits; verified with a meter. fuse Protective device that melts to open the circuit when current is too high. resistor Component that limits or controls current flow. parallel circuit Components connected across the same voltage; current divides among branches. load Any component that uses electrical energy (bulb, motor, heater, etc.). rectifier diode Converts AC current to DC current inside the alternator. relay Electrically operated switch used to control high-current circuits with low current. resistance (R) Opposition to current flow, measured in ohms (Ω) cotter pin a metal fastener used to secure other fasteners, such as nuts or bolts, and prevent them from loosening due to vibration. capacitor Stores electrical charge and releases it when needed. terminal Connection point for wiring or components. continuity test Check to see if a circuit path is complete. switch Manually operated device that opens or closes a circuit. voltage (V) Electrical pressure or potential difference that pushes current through a circuit. oscilloscope an electronic testing instrument that graphically displays electrical signals as a waveform on a screen, showing how voltage changes over time. Multimeter (DVOM) Tool used to measure voltage, resistance, and current. short circuit Unintended path of low resistance causing excessive current flow. circuit breaker Reusable overcurrent protection device. ampere (Amp) Unit used to measure electrical current flow. parasitic draw Unwanted electrical drain from the battery when the vehicle is off. battery Stores electrical energy in chemical form; provides voltage to the system. circuit A complete path for current to flow. series circuit Components connected end- to-end; same current flows through all. Ohm’s Law The relationship between voltage, current, and resistance: V = I × R reference voltage Stable voltage (usually 5V) supplied by an ECU to a sensor. ground Common return path for electrical current; typically connected to the vehicle chassis. stator the stationary coil of wire inside the alternator commutator a reversing switch that keeps the motor turning smoothly by flipping the current direction at just the right time. harness Bundle of electrical wires in protective covering. open circuit A break or interruption in the circuit preventing current flow. connector Device that joins electrical wires or components together. trouble code (DTC) Diagnostic code stored by the vehicle’s control module when a fault occurs. solenoid Electromagnetic switch that moves a plunger or contacts (used in starters). regulator Controls alternator output voltage. EEPROM a type of non-volatile memory used in control modules (ECUs/ECMs) to store data even when the vehicle’s battery is disconnected. current (I) The flow of electrons through a conductor, measured in amperes (amps). watt (W) Unit of electrical power; Power = Voltage × Current. alternator Generates electrical current while the engine runs; charges the battery. continuity A complete path with no open circuits; verified with a meter. fuse Protective device that melts to open the circuit when current is too high. resistor Component that limits or controls current flow. parallel circuit Components connected across the same voltage; current divides among branches. load Any component that uses electrical energy (bulb, motor, heater, etc.). rectifier diode Converts AC current to DC current inside the alternator. relay Electrically operated switch used to control high-current circuits with low current. resistance (R) Opposition to current flow, measured in ohms (Ω) cotter pin a metal fastener used to secure other fasteners, such as nuts or bolts, and prevent them from loosening due to vibration. capacitor Stores electrical charge and releases it when needed. terminal Connection point for wiring or components. continuity test Check to see if a circuit path is complete. switch Manually operated device that opens or closes a circuit. voltage (V) Electrical pressure or potential difference that pushes current through a circuit. oscilloscope an electronic testing instrument that graphically displays electrical signals as a waveform on a screen, showing how voltage changes over time. Multimeter (DVOM) Tool used to measure voltage, resistance, and current. short circuit Unintended path of low resistance causing excessive current flow. circuit breaker Reusable overcurrent protection device. ampere (Amp) Unit used to measure electrical current flow. parasitic draw Unwanted electrical drain from the battery when the vehicle is off. battery Stores electrical energy in chemical form; provides voltage to the system. circuit A complete path for current to flow. series circuit Components connected end- to-end; same current flows through all. Ohm’s Law The relationship between voltage, current, and resistance: V = I × R reference voltage Stable voltage (usually 5V) supplied by an ECU to a sensor. ground Common return path for electrical current; typically connected to the vehicle chassis. stator the stationary coil of wire inside the alternator commutator a reversing switch that keeps the motor turning smoothly by flipping the current direction at just the right time. harness Bundle of electrical wires in protective covering. open circuit A break or interruption in the circuit preventing current flow. connector Device that joins electrical wires or components together. trouble code (DTC) Diagnostic code stored by the vehicle’s control module when a fault occurs. solenoid Electromagnetic switch that moves a plunger or contacts (used in starters). regulator Controls alternator output voltage.
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a type of non-volatile memory used in control modules (ECUs/ECMs) to store data even when the vehicle’s battery is disconnected.
The flow of electrons through a conductor, measured in amperes (amps).
Unit of electrical power; Power = Voltage × Current.
Generates electrical current while the engine runs; charges the battery.
A complete path with no open circuits; verified with a meter.
Protective device that melts to open the circuit when current is too high.
Component that limits or controls current flow.
Components connected across the same voltage; current divides among branches.
Any component that uses electrical energy (bulb, motor, heater, etc.).
Converts AC current to DC current inside the alternator.
Electrically operated switch used to control high-current circuits with low current.
Opposition to current flow, measured in ohms (Ω)
a metal fastener used to secure other fasteners, such as nuts or bolts, and prevent them from loosening due to vibration.
Stores electrical charge and releases it when needed.
Connection point for wiring or components.
Check to see if a circuit path is complete.
Manually operated device that opens or closes a circuit.
Electrical pressure or potential difference that pushes current through a circuit.
an electronic testing instrument that graphically displays electrical signals as a waveform on a screen, showing how voltage changes over time.
Tool used to measure voltage, resistance, and current.
Unintended path of low resistance causing excessive current flow.
Reusable overcurrent protection device.
Unit used to measure electrical current flow.
Unwanted electrical drain from the battery when the vehicle is off.
Stores electrical energy in chemical form; provides voltage to the system.
A complete path for current to flow.
Components connected end-to-end; same current flows through all.
The relationship between voltage, current, and resistance: V = I × R
Stable voltage (usually 5V) supplied by an ECU to a sensor.
Common return path for electrical current; typically connected to the vehicle chassis.
the stationary coil of wire inside the alternator
a reversing switch that keeps the motor turning smoothly by flipping the current direction at just the right time.
Bundle of electrical wires in protective covering.
A break or interruption in the circuit preventing current flow.
Device that joins electrical wires or components together.
Diagnostic code stored by the vehicle’s control module when a fault occurs.
Electromagnetic switch that moves a plunger or contacts (used in starters).
Controls alternator output voltage.
