General description

GENERAL DESCRIPTION

The starting and charging circuit is composed of the battery, starter motor and alternator.

The battery (12V) is of the sealed type and does not require maintenance.

The starter motor consists of a motor supplied DC power supply from the battery and command and engagement solenoid.

When the ignition key is rotated the voltage from the battery supplies the coils of the motor generating the electromagnetic forces which rotate the pinion of the motor itself. At the same time the solenoid is activated and works the engagement mechanism which engages the pinion in the crown wheel of the flywheel thus causing the crankshaft to rotate.

The alternator recharges the battery during normal rotation of the engine. The spindle of the alternator (rotor) which is forced to rotate by the crankshaft through a belt is supplied with the activation current which generates a magnetic field which induces an alternating current on the stator. This is then transformed into direct current by a bridge rectifier with diodes and sent to recharge the battery.

A voltage regulator incorporated in the alternator makes it possible to maintain a constant delivery of voltage (approx. 12 V) for all the fields of variation in loading and engine r.p.m.

FUNCTIONAL DESCRIPTION

When the ignition key is turned in switch B1 to the STARTING position, it activates the coils of the solenoid (pin 50) of the starter motor A11 and with the voltage coming from the battery A1 (pin 30) supplies the actual starter motor, thus starting the engine.

NOTE: In vehicles equipped with an anti-theft device the power supply to the starter motor (ignition key in the STARTING position) crosses the anti-theft device control unit N45 which cuts of this power supply in the event of an alarm.

The DC current generated by the alternator A3 is sent to the battery A1 passing through motor A11.

All the power supply lines of the various electrical systems on the vehicle start from the branch terminal board Q56 connected to the + terminal of the battery A1 (see "Power supply").

When the alternator does not turn and therefore the battery is not being recharged, an earth signal is sent to the instrument panel C10 and illuminates the relative warning light. When the engine is started this signal becomes 12V and the warning light goes out.

TROUBLESHOOTING TABLE