Wiper and Washer Systems: Description and Operation
System IdentificationThe system can be identified by a single electrical lead to the timing circuit.
Operation
The multiplex pulse wiper system provides a controlled wiping action.
The wiper switch in ``DELAY'' mode can be varied from minimum to a maximum position by moving the control knob. The delay can vary from 0 to 12 seconds depending on the position of the knob.
The multiplex pulse wiper motor less the washer pump is the same as the stock standard depressed park wiper motor except for the concealed electrical leads.
When the motor is at LOW speed the motor shunt field is connected directly to ground at the control switch and there is no external resistance.
When the motor is at MEDIUM speed the shunt field is connected to ground through two external resistors (one 20 ohm resistor located in the parking relay and one 13 ohm resistor located in the control switch). The resistors are connected in parallel which provides an equivalent resistance of approximately 8 ohms.
When the motor is at HIGH speed the circuit is open at the control switch and completed to ground through the 20 ohm resistor in the parking relay.
When the motor is in the PULSE or DELAY mode, the parking relay coil ground circuit is maintained at the control switch which keeps it energized. This maintains the 12 volt DC current to the pulse relay coil. The relay coil ground circuit is opened at the control switch and the timing circuit controls the ground circuit.