The electrical system of the Patrol/Maverick series vehicles uses an alternator from Hitachi. The advantage of the alternator is that the battery is charged already at idle speed. When checking the alternator, remember that its rated output current can be either 50 or 60 A, depending on the vehicle model. Hitachi alternator installed on the 4.2L EFI models (since 1992.) has an output current of 70 A and is distinguished by the absence of an external fan.
The generator consists of fixed stator windings, a shaft (rotor) winding, a rectifier diode assembly and a built-in voltage regulator.
When electric current flows through the rotor windings (supplied through brushes pressed against sliding contact rings fixed on the shaft) a magnetic field is induced in it (the rotor). When the rotor rotates, a three-phase alternating current is generated in the star-shaped windings of the stator.
Since the battery can only be charged using a DC power source, the generator is equipped with a diode rectifier mounted in the cover on the slip ring side of the generator.
The output current is determined by the generator's own characteristics, while the output voltage is controlled by a special built-in regulator. It is not possible to adjust the built-in voltage regulator.
To start the engine, one of two types of Hitachi starters is used. Both starters are gear-type, powered by 12 V, and equipped with an overrunning clutch (bendix coupling), which disconnects the starter from the flywheel/drive disk ring gear after the engine has started.
The electromagnetic traction relay is fixed to the bracket of the front cover of the starter. The plunger of the traction relay acts on the assembly of the drive gear with the overrunning clutch through the drive lever.
When power is supplied to the windings of the traction relay, its plunger acts on the drive lever, which engages the drive gear with the flywheel/drive disk ring gear, simultaneously closing the circuit supplying power from the battery to the excitation windings and the armature of the starter electric motor.
After starting the engine, the drive pinion overrunning clutch prevents damage to the electric motor armature as a result of its forced rotation at high speeds when the driver hesitates in releasing the ignition key.