Equipment:
* Voltmeter
* Ohmmeter
* Test lamp
* Current clamp (ammeter)
Steps to check the electrical equipment of a car:
1. Visual inspection
* Check all wires and cables for damage, wear or corrosion.
*Please note any loose or damaged terminals or connectors.
* Check that fuses and relays are working properly.
2. Battery check
* Check the voltage at the battery terminals using a voltmeter. It should be about 12.6 volts when discharged and over 13 volts when the engine is running.
* Check for current leakage using an ammeter by connecting one probe to the negative terminal of the battery and the other to the wire disconnected from the battery. The value must be less than 50 mA.
3. Checking the starter
* Connect the ammeter to the starter and turn the key to the “start” position. Peak current should be around 150-200 amps.
* Check the voltage at the starter during starting using a voltmeter. There must be at least 10 volts.
4. Checking the generator
* Start the engine and measure the voltage at the battery terminals using a voltmeter. It should be around 14 volts under load and above 13 volts at idle.
* Check the charging current by connecting an ammeter to the alternator wire. The value must be within vehicle specifications.
5. Checking cables and connections
* Use an ohmmeter to check the continuity of cables and connections. The resistance should be close to zero.
* Check for grounding using an ohmmeter by connecting one probe to the car body and the other to the wire being tested. The resistance should be close to zero.
6. Checking fuses and relays
* Remove each fuse and check for openness using an ohmmeter.
* Test the relay by connecting a power source to it and measuring the voltage and current using a voltmeter and ammeter.
7. Checking electronic components
Inspecting electronic components such as ECUs or sensors requires specialized diagnostic equipment and knowledge. Contact a qualified mechanic for assistance.