SYSTEM / Electrical System

• When the key switch is turned to the START position, continuity between terminals B and ACC in the key switch is found. Current is supplied to the base in transistor Tr3 through resistance R in the starter relay 2. Transistor Tr3 is turned ON and current is supplied to coil R in starter relay 1. Consequently, battery power is supplied to terminal S in the starter motor from starter relay 1 so that the starter is operated.

• When the engine is started, the alternator begins charging and the pulse wave pattern of the frequency in proportion to the engine speed is output from terminal P in the alternator.

• When this frequency reaches 170 Hz (alternator rotation speed is 1700 r/min), transistor Tr3 is turned OFF as no current is supplied to the base in transistor Tr3. Current to coil R in starter relay 1 is stopped at this time so that the starter is turned OFF.

T2-3-12