Note. It is easier to check the correct installation of the generator and the absence of play if the accessory drive belt is removed (see section «Engine»).
Overrunning clutch test
An overrunning clutch installed between the rotor shaft and the pulley allows the generator rotor shaft to rotate freely in one direction. This means that jerks in the belt drive are reduced to a minimum.
A malfunctioning freewheel can cause the following symptoms:
- the low battery warning lamp is on when the engine is running;
- the battery is discharging;
- noise from the belt drive is heard;
- engine vibrates when accelerating;
- the engine runs unevenly at idle;
- noise is heard from the generator.
Note. If the alternator has a cover over the pulley nut in the center, then it has an overrunning clutch installed.
Checking the operation of the overrunning clutch on the car
Make sure that no additional power consuming components are connected. Turn on the ignition. Bring the engine speed up to 3000 rpm.
When the freewheel comes into contact with the rotor shaft, and out of it, only a slight click is heard.
Switch off the ignition quickly. Make sure that the rotation in the generator continues longer than in the engine.
Note. In cold weather, the battery charge warning light may come on shortly after starting the engine. This is due to the fact that the freewheel must begin to rotate and warm up the bearing lubricant in order for the rotor shaft to lock and actuate. If the lamp stays on, this may indicate that the freewheel has not engaged the pulley on the rotor shaft.
Checking the operation of the overrunning clutch on the removed generator
Rotate the pulley counterclockwise, then stop it abruptly. The freewheel must engage the rotor shaft when rotating counterclockwise.
Stop rotation by braking the pulley. When the pulley is braked, the freewheel mechanism must be released so that the rotor shaft continues to rotate.