Vehicle check. To check, you must have a DC voltmeter with a scale of up to 15-30 V with an accuracy class of at least 1.0.
After 15 minutes of engine operation at medium speed with the headlights on, measure the voltage between the terminal «B+» and generator weight. The voltage should be within 14.75±0.15 V.
In the event that a systematic undercharging or overcharging of the battery is observed and the regulated voltage does not fit within the specified limits, the voltage regulator must be replaced.
Checking the removed regulator. The regulator assembly with the brush holder, removed from the generator, is checked according to the diagram shown in fig. 7-11.
Pic. 7-11. Scheme for testing the voltage regulator:
1 - control lamp;
2 - output «weight» voltage regulator;
3 - output «DF» voltage regulator;
4 - voltage regulator;
5 - output «D+» voltage regulator;
A - to the power source.
Between the brushes, turn on the lamp 1-3 W, 12 V. To the conclusions «D+» And «weight» regulator, connect the power supply first with a voltage of 12 V, and then with a voltage of 15-16 V.
If the regulator is working, then in the first case the lamp should be on, and in the second it should go out.
If the lamp lights up in both cases, then there is a breakdown in the regulator, and if it does not light up in both cases, then either there is an open in the regulator, or there is no contact between the brushes and the outputs of the voltage regulator. The latter can be checked by connecting the wires from the lamp not to the brushes, but directly to the terminals «D+» And «DF» voltage regulator.