Chevrolet Repair: Wiper Motor Crank Arm Postion, crank arm, gmc 1500

Question
I replaced a defective wiper motor on my 1998 GMC 1500 Pickup. I removed the wiper motor crank arm from the old motor and placed it on the new motor however, I am not sure if the crank arm was positioned on the motor properly.  I had to make numerous adjustments to the drive rods to get the wipers to move in the required range but I still have problems with wipers slapping at both ends of the stroke.  Could I have incorrectly positioned the wiper motor crank arm, or is there a process which needs to be followed to get the motor, crank arm, drive rods and wipers working without all the noise and slapping?

Answer
Hi Paul....yes there is....take off arm attached to the motor....make sure wiper arms are all the way down...with arm off turn on wipers then shut off...the motor should now be in park....when looking at the arm make sure when you put it back on the motor the arm will move the wiper arms up...when you turn on motor...make sure you know which way motor turns when on....hope this helps