Headlamp Wiper Fault

Got a strange issue tonight with Left Headlamp Wiper. Motor starts & stops every minute or so for no reason, and wiper blade not moving.

Left wiper shaft feels stiff, but no resistance from gears in the motor. Right side works fine, and I can feel the resistance of the gears.

Searching here & RR.net seems to point to duff motor, or headlamp washer pump, so I'm gonna take it out in the morning an have a look, but in the meantime has anybody got any ideas ?

Could it be trying to park, but never getting there ?

Just guessing here as I have never had to strip one down but, if the wiper runs through gears from the motor and the wiper spindle has seized then it may have stripped the gear cogs of teeth. Take it out and have a look.