The windshield wipers on my 1993 mustang will only work on one speed (High). I put a new motor on the car, because the wipers had stopped working altogether, but the new one only works on high. If you unplug the three plug wire on the motor the wipers do speed up to what I would call high speed, but that is the only improvement that I get. If you unplug the two plug wire from the motor, the wipers do not work at all. There is a small two plug wire that comes out of the wiper wiring harness, but I do not see any place for it to go. I did have a different switch for the inside that I tried, but that did not help either. GOT ANY SUGGESSTIONS?