Windshield Wiper Motor; Interval Wiper Relay Circuit; 2-Speed Type - Suzuki Samurai 1986 Service Manual

21-4. WINDSHIELD WIPER MOTOR

CIRCUIT DESCRIPTION
The circuit is designed so that, when the Wiper Switch is turned "OFF", the blade will automatically return
to the horizontal position. In Fig. 21-11, when the Wiper Switch is turned "ON" while the Main Switch is
"ON", current is supplied to the Wiper Motor from the Battery, the motor rotates and the blade moves.
The gear mechanism which converts rotational movement of the motor into swinging movement of the
blade has a cam on the final gear shaft. The cam switches the contacts of P0 and P2 every revolution.
(At the blade stop position, the contact is switched from P2 to P1.)
Repeated contact making and breaking is independent of the wiper motor rotation. When the Wiper Switch
is turned "OFF" while the blade is in a position other than the rest position, motor current path is changed
(i.e. BI/W + BI + MOTOR). Therefore, the motor keeps rotating even though the wiper switch is turned
"OFF", and the blade will return to the rest position.
When the blade returns to the rest position, the cam contact is changed from P2 to P1 and motor current
is shunted. When supply to the motor is cut off, a counter electromotive force is generated in the
armature. As a result of this counter electromotive force, current flows through the motor and shunt
circuit and the motor stops and the wiper blade stays in the specified position.
[INTERVAL WIPER RELAY CIRCUIT (OPTIONAL)]
When the wiper switch is set to the interval position with the ignition switch ON (the condenser is charged
at this time), current from the battery flows through the yellow/blue wire, generates magnetic force in the
coil in the relay and causes the switch in the relay to turn ON. Then current is transmitted in the sequence
of yellow/blue, relay, wiper switch and blue and causes the wiper motor to rotate (meanwhile, the conden-
ser discharges). By the time the wiper motor makes one rotation and the cam in the motor comes to the
automatic stop position P1, the condenser in the relay has finished discharging (no magnetic force in the
coil in the relay). Then the switch in the relay turns OFF and the wiper stops. They remain that way until
the condenser is fully charged. As soon as the condenser begins discharging after being fully charged,
magnetic force generated in the coil in the relay causes the switch to turn ON. As described above, interval
operation of the wiper motor is controlled by charging and discharging of the condenser.

2-speed type

OFF
LOW SPEED
HIGH SPEED
Fig. 21-11
6
1. Battery
2. Main switch
3. Fuse box
4. Wiper motor
5. Wiper switch
6. Washer switch
7. Washer motor
: Blue
21-9