regularly, the front windscreen wipers won't park correctly, so will stop on intermittent, or, when you switch the wipers off, they take a few sweeps to stop.

Is there a position sensor on it, that is playing up??

 

most likely bad switch. I seen where the park circuit in the wiper motor cause a parking problem

 

is it a user serviceable part?

 

IMHO (in my honest opinion) every single part/component/system of any vehicle could be "user serviceable". Depends on the mechanical aptitude of said user.

 

OK, I will rephrase the question, is the parking switch of the wiper mechanism changeable, and do Chrysler actually sell the part, or do you have to dismantle the whole wiper assembly to replace it.

 

no, that part of the wiper motor is all inclusive to the motor. But it wouldn't be the first possible cause of wiper malfunction, the switch is more common. Using rational and pragmatic problem solving skills would be required to determine the true cause of the failure

 

Right, so the switch, that indicates to the BCM, when the wipers are in the 'parked' position, is built into the motor? So to change it, would mean changing the wiper motor?

As for 'other faults' it isn't the switch on the dash, as that opearates correctly, and there is no play in the mechanism.

 

wrong!. The wiper switch that the operator manipulates to control the wipers, could be defective. It sends a signal to the BCM which the BCM sends an output to the wiper motor. Now inorder to "park" the wipers, the BCM sends a signal to the wiper motor to park the motor. if the control within the wiper motor does not function properly, it will stop where ever the on power is interrupted.

What you need to do is get a wiring schematic and see if you can comprehend how electrical system of the wipers works. Also get a factory service manual and there is a complete logical and pragmatic problem solving sequence to direct you to the answer to this delema