- An electrical consumer that is not working is not supplied with current.
- The consumer himself does not work.
- The consumer is poorly grounded.
The first category of faults are the most complex. This is the power supply system, which contains all the switches, relays, fuses, etc.
The electrical circuit can be checked with a test light with detachable wires on the other end that have alligator clips on them.
If the lamp does not work, follow a systematic approach to determine which of three causes is at play:
Turn on the switch that connects the non-working lamp.
Disconnect the power supply wire from the lamp.
Connect the test light's ground wire to a good metal ground.
Touch the test tip of the test lamp to the end of the power supply wire that was disconnected from the lamp. If current is supplied to the lamp, the test lamp will light.
CAUTION: If the lamp only comes on when the ground is turned on, make sure the ignition key is turned to the "on" position.
If the test lamp does not light, then the fault is in the circuit between the battery and the lamp. As noted above, this includes all switches, fuses, relays, etc. Find this lamp on the electrical circuit diagram and follow how the voltage approaches it. The fault is in the break in the circuit between the battery and the lamp. If the fuse has blown and immediately blows again when replaced, this means a short circuit in the circuit, which must be found and eliminated. If the system has a switch, bypass it (short-circuit it to the "on" position) using an auxiliary wire, connecting it to the wire coming out of the switch. If the test lamp lights up, then the switch is faulty.
[The article is based on data from the website MitsubishiMan.ru]
CAUTION: Never replace the auxiliary wire with a light bulb, as it requires battery power.
If the test lamp does not light, then the current is supplied to the lamp, i.e. the first of the possible causes is excluded. Connect the wire supplying the voltage and connect the ground on the car body with the ground on the lamp with an auxiliary wire. In this case, the switch connecting the lamp must be in the "on" position and the ignition must be on. If the lamp being tested only works when the ignition is on, this indicates poor grounding. This is usually caused by the fact that the metal surface on which the lamp is attached is covered with a layer of foreign origin (paint, rust, etc.).
If none of the checks give a result, then the lamp itself is faulty. The above procedure can be used for any electrical consumer of the circuit by replacing this faulty consumer with a light bulb. Remember that for reliable operation of the electrical circuit, the connection points must be clean and tight.