Basic Eletrical Fundamentals
The flow of electrical current through a circuit is called this.
What is current?
The number one tool used to test voltage, resistance, and continuity.
What is a multimeter?
The component that starts the electrical system when the key is turned
What is the battery?
This protects a circuit from too much current.
What is a fuse?
The starter only clicks once. Battery is good. What should you check next?
What is voltage drop on the starter’s positive and ground circuits?
The force that pushes electrons through a circuit.
What is voltage?
This tool is used to safely check for unwanted current draw when the vehicle is off.
What is an ammeter or parasitic draw tester?
This component charges the battery while the engine runs.
What is the alternator?
A device used to open or close a circuit using a small electrical signal.
What is a relay?
A blower motor works on high speed only. This usually indicates what failed component?
What is the blower motor resistor?
This measurement represents resistance in a circuit.
What are ohms?
Before using a scan tool, you must always check this basic thing first.
What is battery voltage?
These two types of sensors are the most common in modern vehicles.
What are voltage (DC) sensors and resistance-based sensors?
Before unplugging any connector, you should make sure of this
What is the ignition is off?
Brake lights stay on even when the vehicle is off. What is the most common cause?
What is a faulty brake pedal switch?
In a series circuit, if one component fails, this happens to the entire circuit.
What is the whole circuit stops working?
This tool sends power to a component to see if it works without using the vehicle’s wiring.
What is a power probe?
This system uses fuses, relays, and modules to control how power is distributed.
What is the power distribution system?
These charts help you trace wiring paths and locate power, grounds, and splices.
What are wiring diagrams?
After repairing wiring, several modules won’t communicate. What must be inspected?
What is CAN wiring polarity, continuity, and resistance?
This law states that V = I × R.
What is Ohm’s Law?
This setting on a digital multimeter should be used to test if a wire is connected from end to end.
What is continuity mode?
These computers control everything from engine timing to communication between modules.
What are ECUs or control modules?
This type of circuit has more than one path for current to travel.
What is a parallel circuit?
A customer reports the battery dies overnight. You find a parasitic draw that disappears when a specific fuse is removed. What does this tell you?
What is the fault is in the circuit powered by that fuse?