Malfunctions of the car's electrical equipment can be divided into problems of operation of current sources (batteries, generators) and electricity consumers (options, ignition). Malfunctions of electrical equipment are often encountered and are determined by such signs as engine starting difficulties, headlight failures (dimness or change in brightness without driver intervention), activation of the battery charge indicator, whistle in the drive belt or its overheating, uncharacteristic noise from under the hood, typical electric noise. Diagnostics of the car's electrical equipment is carried out with the help of devices and is aimed at finding contact faults in connections, closing circuits due to conductor insulation failure, as well as failure of electrical circuit elements, including sensors of control and measuring instruments.