- the battery must be fully charged;
- all consumers, except for the battery and the ignition system, must be turned off;
- engine speed should be 2500-3000 rpm.
Measure the voltage at the battery terminals. If the voltage does not exceed 14.5 V, the regulator is OK. At a higher voltage, the regulator housing is connected to the car body with a separate conductor and the voltage is measured again.
If in the second case the voltage is again increased, then the regulator is faulty and must be adjusted or replaced. If the voltage is normal, then the reason for overcharging the battery is a poor connection of the regulator housing to ground.
A regulator malfunction can be determined by checking its internal parts. The reasons for the failure of the regulator may be the following:
- break in the temperature compensation resistor R1 (see fig. 153) or regulator winding. In this case, the voltage is not regulated and rises excessively. This fault can be detected by measuring the electrical resistance between the plug "15" and foundation;
- break in the inductor winding Dr or in an additional resistor In this case, the regulation is unstable (sudden voltage fluctuations). The fault is detected by checking the electrical resistance between the plugs "15" And "67" with open contacts of both the 1st and 2nd stages;
- contamination, burning or oxidation of the contacts of the 1st and 2nd stages, when the regulated voltage is unstable. The malfunction may be caused by the penetration of foreign substances into the regulator (oil, petrol, water), that contaminate the contacts, or a short circuit in the wire circuit of the plug "67" or in the excitation winding of the generator. Foreign matter entering the regulator is due to improper installation or deterioration of the gasket between the cover and the base of the regulator, or if the gasket is made of the wrong material and does not provide a reliable seal or releases volatile substances. If the contacts are damaged, it is recommended to check the condition of the circuits (short circuits and correct wiring), as well as the health of the generator.