Wiper help.

Got an annoying problem with the defender. First the problem....My wipers won't Park properly. They will move on every setting (intermittent, slow,fast) but not Park. On intermittent they will carry on for a second or two after I turn them off but always Park in a different position each time. And when I use slow or fast they just stop as soon as I turn them off.
I have just replaced the park switch on the back of the wiper motor with a new one but still no luck. Could it just be it's a faulty new switch? Relay at fault and if so which one is it? Stalk? Or something to do with the internal working of the motor itself?
Just seeing if anyone has had a similar problem after changing the park switch so I can fix it with minimal fault finding myself.

Take the switch off the motor and operate it. The wipers should start and stop. If that's OK, then it's in the motor's gearbox that the problem lies. There's a wheel with a track that the switch runs on. There's either a lump or a recess on it that operates the switch and turns it off when it gets there, and your's doesn't.

I have the same problem thought it was the park sensor but the sensor is fine wiper motor works fine just parks wiper in centre of screen anything else that could cause this.