Learn Automotive Electrical Diagnostics and Repairs

Learn how the alternator charges the battery and powers the electrical system, tracing cables from the battery to the alternator, inspecting its components, brushes, and output around 14 volts.

Explore how the starter motor, an electric component powered by the battery, engages the flywheel via solenoids and a switch to crank the engine.

Explore automotive cooling systems, focusing on the thermostat and cooling fan operation, radiator loops, and the water pump, and how temperature sensing controls cooling to safeguard the engine.

Explore how the ignition system generates a spark to ignite combustion, times it with the crankshaft, and uses distributor, spark plugs, cables, and a 12-volt battery, and explains misfiring.

Learn how sensors convert mechanical energy to electrical signals and how actuators, such as windshield and window motors, drive vehicle motion for auto electrical diagnosis.

Explore electric windows and their actuators, remote control systems, and the modeling of control data layers for automotive electrical diagnostics and repairs.

Learn how electric horns function and how to inspect their wiring and fuse connections, including the positive terminal and body ground, to diagnose and repair electrical horn systems in vehicles.

Explore how electronic control modules interpret sensor signals and issue commands to vehicle systems, including ECM/ECU, PCM, body and powertrain controllers, and the CAN bus.

Explore the features and functions of a multimeter for automotive diagnostics, including resistance, DC/AC voltage, continuity tests, and safe testing practices.

Use automotive test lights to indicate power in circuits, test fuses, and observe power flow between battery terminals and ignition, noting that indicators do not show current or voltage.

Learn how fuses and relays protect vehicle circuits by limiting current and enabling safe power distribution, with an overview of fuse box and relay locations, IP ratings, and fault diagnosis.

Use a multimeter to test relay resistance by placing leads on the relay terminals; polarity doesn't matter, and a typical healthy reading falls between 50 and 200 ohms.

Learn how to test relay resistance when energized using a multimeter, interpret readings from testing leads, and verify circuit continuity without a voltage source.

Learn how to perform a relay voltage test by wiring power to the relay, connecting a load, and verifying voltage across the terminals.

Explore how to read automotive wiring diagrams, identify symbols for power and signals, trace current paths, and understand components like batteries, circuit breakers, ignition switches, relays, and sensors.

Learn how to inspect the vehicle's ECU in automotive electrical diagnostics and repairs and diagnose starting issues using a diagnostic tool, checking ignition and PCM signals, connectors, and internal circuitry.

Learn how automotive sensors such as crankshaft and temperature sensors work and diagnose them via resistance tests, continuity checks, and identifying power, ground, and signal pins with a multimeter.

Explore vehicle sensors and how they work, including crankshaft position sensors, temperature sensors, and fuel level sensors, with practical back probing and resistance testing techniques.

Walk through a 4-pin mass airflow sensor, identifying the four cables (power, supply, and signal) and testing them using a Mercedes-Benz example.