Before tackling any faulty electrical circuit, first study its wiring diagram to fully understand what it consists of. For example, it is sometimes possible to significantly narrow down the troubleshooting scope by checking the operation of other components associated with the circuit. If several components or circuits fail at once, then it is possible that the problem is in the fuses or in the ground, because. often several circuits pass through the same connection of fuses and ground wires.
Faults in electrical circuits usually come from simple causes such as loose or oxidized contacts, a blown fuse, a melted fuse, or a failed relay. Therefore, before you start looking for damage, visually check the condition of all fuses, wires and contacts in a faulty circuit.
The basic tools needed to troubleshoot an electrical circuit include a tester, a high-resistance digital voltmeter, a continuity tester, and wires from a jump start kit with a built-in circuit breaker that is used to bypass circuit components. Before attempting to troubleshoot with test tools, look at the wiring diagram to determine where to connect them.
Checking the voltage in the circuit
A voltage test is done when the circuit is not functioning well. Connect one end of the circuit tester to the negative battery cable or to a good ground.
Connect the other end to one of the connectors on the circuit under test, preferably the one closest to the battery or fuse. If the tester light is on, then there is voltage in the circuit, which, in turn, means that there is no malfunction in the circuit between the connector and the battery. Continue to check the remaining sections of the chain in the same way.
When you reach an area where there is no voltage, you will find the fault location. Most often, the problem is in poor contact.
Be aware that some circuits are only energized when the ignition is on.
Finding a fault in a circuit is a fairly simple matter if you remember that any electrical circuit is electricity flowing from the battery through wires through switches, relays, fuses and fuses to various components of the electrical circuit (light bulbs, motors, etc.) and to ground, from which it passes back to the battery. And any malfunction in the circuit is a violation of the flow of electricity from the battery or to the battery.
Search for a short circuit
One method for finding a short circuit in a circuit is to disconnect the fuse and connect a test light or voltmeter in its place. There should be no voltage in the circuit. Move the wiring from side to side while watching the test light. If the light turns on, it means that there is a short circuit to the ground in this area, probably the insulation has been worn somewhere. Each component of the circuit is also checked, up to the switch.
Grounding check
Perform a ground test to check if the circuit component is properly grounded. Disconnect the battery and connect one end of the continuity tester to a good ground. Connect the other end to the ground wire or connector to be tested. If the light comes on, then the grounding is done correctly. If it doesn't light up, then it's wrong. In this case, disconnect the connector and thoroughly clean all connecting parts. When reconnecting the connector, use serrated washers if possible and securely tighten all bolts and other fasteners.
If your vehicle's radio is equipped with an anti-theft system, make sure you have entered the correct code before disconnecting the battery cable. See section for information Anti-theft audio system and instrument panel language before disconnecting the wire.
If after connecting the wire on your instrument panel there are inscriptions in the wrong language that you need, refer to Section Anti-theft audio system and instrument panel language, for instructions on how to set the desired language.
Checking the conductivity of the circuit
Checking the conductivity of the circuit is carried out to determine if there are any breaks in the circuit - whether it conducts current well. To check, a conductivity tester is used, the current in the circuit is turned off. Attach lead wires to both ends of the circuit, and if the test light comes on, the circuit is conducting well. If the light does not come on, then there is an open somewhere in the circuit. The same procedure is used to test the switch, only the conductivity tester is connected to the switch terminals. When the switch is on, the light should come on.
Open circuit search
When visually determining the location of a possible opening of the circuit, difficulties often arise, because. oxidation or misalignment of the contacts is hidden by the connectors. An open circuit is often caused by oxidation or loose contacts. Simply by moving the connector pin on the sensing element or in the wiring, an open circuit can be restored, at least temporarily. Disconnect the connector and spray it with water from an aerosol can. On simple connectors, it is sometimes possible to carefully bend the connector pins inward to improve contact - however, be careful not to overdo this or damage the connector.