There are two types of circuit damage: open circuit and short circuit.
When a break occurs, the circuit is opened and power is not supplied to the electrical appliance. Sometimes a break is very difficult to detect because the housing of the connector block hides oxidized contacts or an incorrect connection. In addition, a break can be detected by shaking the pads or wiring harness. This must be taken into account if there are signs of a break or intermittent operation of the electrical appliance.
A short circuit is an unacceptable connection of a part of a circuit to ground or another part of the circuit. Typically, a short circuit results in a blown fuse or electrical appliances turning on by themselves.
After repairing the electrical wiring, it is necessary to check the circuit by turning on the electrical appliances included in this circuit. This confirms not only the correctness of the repair performed, but also the correctness of the diagnostics performed when searching for a fault.
Checking the integrity of the circuit
The integrity of the circuit is checked using a multimeter in ohmmeter or continuity mode. The multimeter leads are connected to the ends of the circuit being tested. If the circuit is intact, the multimeter will emit a beep in the continuity test mode (see the multimeter operating instructions). In ohmmeter mode, if the circuit is intact, the resistance will be minimal, and if there is an open circuit, the resistance will be very high (strive for infinity).
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Short circuit detection
If there is a suspicion of a short circuit in any section of the circuit, disconnect this section from the rest of the vehicle's wiring by disconnecting all of its connecting blocks. We connect one terminal of the multimeter in the circuit test mode to the section of the circuit being tested, and the second to the vehicle ground. If the circuit is closed, then there is a short circuit in this section of the circuit, which must be found by carefully inspecting the entire section of the circuit (wiring harness).
If a short circuit occurs due to damage to the wire insulation, it can be eliminated by restoring the wire insulation using electrical tape.
Often the cause of a short circuit is severe oxidation of the contacts in the connection blocks. In this case, it is necessary to thoroughly clean or replace the contacts. Before connecting, it is better to treat the contacts with a special conductive grease.