900 S Convertible L4-2290cc 2.3L DOHC EFI (1997)
Starter Motor: Description and Operation
Principle of Operation
Components
1. Battery 1
2. Starter motor 4
3. Ignition switch 20
4. Fuse holder 22 A
5. Starter relay 517
The starter motor circuit is extremely simple in design. It consists of two sub-circuits:
-
working circuit
-
operating circuit
Working circuit
The working circuit goes from the positive battery terminal to terminal 30 on the starter motor, through which the solenoid is supplied with working
current.
Operating circuit
The operating circuit goes from the positive battery terminal to the ignition switch and on to the starter relay, and also via the starter relay to terminal 50
on the starter motor, through which the solenoid is supplied with operating current.
Principle of operation
When the ignition switch is turned to the Start position the starter relay operates, closing the operating circuit to the solenoid via terminal 50.
The solenoid moves the pinion into engagement with the ring gear, closing the main contacts so that the starter motor commutator is supplied with
current from terminal 30 via slip-rings and brushes.
Once the engine starts, the flywheel will soon exceed the speed of the starter motor. This causes a free-wheel to disengage the pinion from its shaft and
so prevent overrevving of the starter motor.
Releasing the ignition key breaks the starter circuit and also breaks the operating circuit to the solenoid. A spring then returns the pinion to its rest
position.
