Tools for checking electrics in a car:
* Multimeter
* Test lamp
* Diagnostic scanner (optional)
Steps to check electrics in a car:
1. Safety First: Make sure the vehicle is parked on a level surface, the parking brake is set, and the ignition key is in the off position.
2. Battery check:
* Use a multimeter to measure the voltage at the battery terminals. There should be a minimum of 12.6 volts with the engine off and a minimum of 13.5 volts with the engine running.
* Check the battery terminals for corrosion or looseness. Strip and tighten terminals as necessary.
3. Checking fuses and relays:
* Locate the fuse box and relay box in the vehicle. They are usually located under the hood or in the cabin.
*Use a multimeter to measure the conductivity of each fuse on the circuit. Blown fuses will have zero conductivity.
*Remove the relays and check their contacts and coils with a multimeter for continuity.
4. Wiring check:
* Visually inspect the wire wrap for damage, breaks, or exposed areas.
* Use a multimeter to check the continuity of wiring between different points.
* If the device shows a lack of continuity, it is necessary to find and eliminate the break.
5. Grounding check:
* Using a multimeter, check the resistance between the negative terminal of the battery and a metal part of the vehicle chassis. Resistance should be minimal.
*If resistance is high, check grounding points for corrosion or poor connections.
6. Checking electronic components:
* Use a diagnostic scanner to read fault codes from electronic components such as the ECU (Engine Control Unit) or ABS (Anti-Lock Brake System).
*If there are fault codes, review the repair manual to diagnose and resolve the problem.
7. Checking the generator and starter:
* To test the alternator, use a multimeter to measure the voltage at the alternator output while the engine is running. The voltage must be at least 13.5 volts.
* To test the starter, turn the ignition key to the “start” position and measure the voltage at the starter terminal using a multimeter. There must be at least 10 volts.
Adviсe:
* Wear gloves when working on the electrical system.
* Disconnect the battery before performing any major checks.
*Refer to your repair manual for specific values and procedures for your vehicle.
*If you are unsure of your electrical skills, consult a qualified mechanic.