1992 Plymouth Voyager rear wiper. when I turn switch on the wiper goes half way and after a pause goes the rest of the way and then after a pause goes back half way and after a delay goes back the rest of the way. Cycle repeats. I installed another wiper delay unit but the wiper still does the same thing. My original wiper motor kept blowing fuses so I replaced it with a used unit. When tested alone, the wiper goes thru the normal full back and forth cycle. What is causing the half way delay each way ??? Thanks.