Windshield Wiper problems

I went through the carwash today, and when I came out and was on my way home the wipers came up from there parked posistion like i had put them on intermittent, but when i tryed to function the wipers nothing happened, even the washerfluid function failed to move them, so i drove straight to the dealership and on my way there they parks again and then instantly repositioned again, so i took the oppurtunity and messed around with the wiper stick and they started to reluctantly work stopping every once in a while in random spots and after a couple of minutes on high they returned to perfect working order??? any ideas?? i would hate to have them go out in a downpour..

Where do they stop when you turn them off? Mine worked fine till I turned them off. if this is the case, do the following:

If you pull the wipers and the cover on drivers side, getting down to the motor, look where the arm hooks onto the motor. Down below the unit the arm connects to, look to the bottom and see if you can find a tab that is in a bracket and pry outward. When you cycle the wipers and turn off, this tab hits a piece of metal bent up and changes the direction to the transmission and stops in the right position. This happened to me when too much snow was on windshield a couple years ago and just found it.