by Ed Esslinger in the July 2003 RootesReview
Let’s say it is raining. You turn on your wipers and every thing is OK. Now you park and you forget to turn off your wipers to let them park before you turn off your ignition switch. When you turn off the ignition switch everything stops (If you put on your brakes) including the wipers, wherever they happen to be at that time. Now a few days later the windshield is dry and dirty or worse, the blades are frozen to the windshield. The wipers will start or try to, as soon as the ignition switch is turned on. Even if you turn off the wiper switch before you turn on the ignition switch, the wipers will run or try to run to the park position across that dry and dirty windshield as soon as the ignition switch is turned on!
I have a fix for this problem. With the addition of the circuit you are about to read about, anytime the ignition switch is turned off the wipers will go to park, and will not turn on again unless the wiper switch is first returned to the off position.
Running the wipers continuously when there is only enough mist to obscure your vision is another cause of windshield scratching. In this design I have incorporated another circuit that has the ability to give intermittent operation (interval can be adjusted) in place of the slow speed selection of the wiper switch. Normal speed is unaffected. The circuits fit in a tube 1-1/4”x 4” and can be installed or removed in about 20 min with no cutting or splicing of any wires.
There is also an optional regulator circuit for the gauges that can be installed in the unit.