To find the correct park position for your wiper,first park the motor by turning the wiper off at the control stalk,remove the complete assembly, then slacken the nut which holds the crank onto the motor shaft(you will have to free the taper with a sharp hammer tap on the nut), move the drive head to the park position(there are index marks on the back of the drive head under the rubber seal) then retighten the motor crank nut while keeping everything in position ; the motor crank and drive link should be parallel to each other.
Refit using just the bottom nuts to check operation , then if ok refit properly , lubricate all the sliding mechanism under the turtle shell and job done.
Don't know about your problem with intermittent wipe, but if you have fitted a new relay I think the fault must be in the stalk switch.
Geo.