Can anyone tell me the difference between a modified pulse wiper system and a multiplex wiper system. I am converting my 78 SS over to delay wipers and have obtained a complete modified system, motor,washer, and all wiring..

Also, what years where each of the above used in??

Thanks for any help you may be able to give me on this..

What year did they start to use the turn signal stalk for the wiper system?


Sonny

Modified Pulse System
Models equipped with pulse wipers use a motor similar to the one used on standard wiper systems which has been modified to provide a delay wipe mode. In addition to standard wiper system components, the modified pulse system includes a voltage feed circuit to the wiper switch and a variable resistor in the switch, a pulse relay and holding switch mounted on the washer pump, and a timer circuit. The timer circuit, consisting of a capacitor, transistor and two diodes, is mounted in the washer pump or contained in a separate module.
The gearbox relay functions in a similar manner on both standard and pulse systems, but on pulse systems the gearbox relay supplies voltage to the pulse relay which controls current flow to the motor windings. In all wiper switch positions except delay, the gearbox and pulse relays are grounded simultaneously through the wiper switch, and the motor operates as outlined in ``Standard (Non-Pulse) Wiper Operation.'' When wiper switch is in delay position, pulse relay operation is controlled by the timer circuit.
Placing wiper switch in delay position grounds gearbox relay terminals 1 (relay) and 3 (shunt field) at the switch, and battery voltage is supplied to the timer circuit capacitor through the variable resistor in the switch. When the capacitor is fully charged, it activates the timer transistor. The transistor completes the pulse relay ground circuit, and current flows through the motor windings. As the motor begins to operate, holding switch contacts close, the capacitor discharges partially, and the pulse relay ground is maintained through the holding switch. As wipers complete their cycle, a fin on the washer pump drive cam opens the holding switch. This stops the motor and allows the timer capacitor to recharge.
This cycle repeats as long as wiper switch is in delay position. Delay between wipe cycles is determined by controlling charging current to the capacitor through the switch resistor. Higher resistance produces longer delay.



Multiplex Wiper System
Models with pulse wiper use a motor similar to the one used on standard systems, but with modifications to provide a delay wipe mode. The multiplex system, while similar to earlier pulse wiper systems, uses an integrated circuit timer and the voltage feed to the wiper switch has been eliminated. In addition to standard wiper system components, the multiplex system uses a variable resistor in the wiper switch, a pulse relay and holding switch mounted in the washer pump, and a timer circuit. The timer, consisting of a capacitor and integrated circuit, is mounted on a circuit board in the washer pump or contained in a separate module.
The gearbox relay functions in a similar manner on both standard and multiplex systems. However, on pulse systems the gearbox relay supplies voltage to the pulse relay, current to the motor windings is controlled by the pulse relay, and voltage is supplied to the timer circuit from motor terminal 2. In all switch positions except delay, the gearbox relay, pulse relay and timer capacitor circuits are completed directly to ground through the wiper switch. This deactivates the timer circuit and allows the motor to operate as outlined in ``Standard (Non-Pulse) Wiper Operation.''
Placing wiper switch in delay position grounds gearbox relay terminals 1 (relay) and 3 (shunt field), and the timer capacitor is partially grounded through the variable resistor, allowing it to charge at a controlled rate. When the timer capacitor is fully charged it activates the integrated circuit. The integrated circuit completes the pulse relay ground circuit, and current flows through the motor windings.
As the motor begins to operate, holding switch contacts close, the capacitor discharges partially, and the pulse relay ground is maintained by the holding switch. As wipers complete their cycle, a fin on the washer pump drive cam opens the holding switch, wipers stop and the timer capacitor begins to recharge. This cycle repeats as long as wiper switch is in delay position. Delay between wipes is determined by varying resistance between the timer capacitor and ground.