Insufficient belt tension impairs battery recharging and leads to increased belt wear.
If the belt is too tight, the alternator bearings may fail.
The scheme for checking the tension of the alternator drive belt is shown in the figure:
The alternator drive belt must bend 10–15 mm at a force of 100 N (10 kgf), applied in the middle between the pulleys of the crankshaft and the generator. Otherwise, adjust its tension.