The scheme for a more detailed study consists of two parts
Electrical equipment failures are often due to the simplest causes, such as corrosion of connector contacts, fuse failure, fuse blown, or relay damage
When using diagnostic tools for troubleshooting, carefully plan (in accordance with the attached electrical diagrams) where and in what sequence the device should be connected in the loop for the most effective troubleshooting.
The main diagnostic tools include an electrical circuit tester or voltmeter (you can also use a 12-volt test lamp with a set of connecting wires), an open circuit indicator (probe), which turns on the lamp with its own power source and a set of connecting wires.
In addition, you should always have a set of wires in the car for starting the engine from an external power source (the battery of another car), equipped with crocodile clips.
As already mentioned, before starting to check the circuit using diagnostic equipment, determine the connection points from the diagrams.