As a sensitive device, the wiring harness is easily affected by the interference source of the whole vehicle. Typical vehicle interference sources include parts such as the ignition system, electric motor, converter, and antenna.
The engine ignition system is mainly composed of batteries, ignition coils, spark plugs, capacitors and other components. When the car is ignited, the current in the battery enters the primary coil, and under the action of the coil cell, the secondary coil generates an induced current. When the induced current in the secondary coil continues to increase, so that the spark plug gap is broken down, the energy stored in the spark plug capacitor is quickly released. This discharge process causes a sudden increase in the current on the side of the secondary circuit, radiating electromagnetic waves to the surrounding environment space.
Electric motors are widely used in complete vehicles, including wipers, water pumps, seat adjustments, and rearview mirror adjustments. The commutator of the motor commutates in the magnetic field and the switch contacts open and close repeatedly during operation, which makes the motor release a large amount of electromagnetic waves to the surrounding environment. Even with the shielding of metal objects, the electromagnetic waves transmitted by the motor through conduction cannot be underestimated.