The motor on mine was actually wet in side, if you measure the resistane across the 2 purple wires the the motor plug ( they are you temperature sensor ) it should read over 50K ohms i think ( sorry i cant remenr exactly the value ) But the code reader i posted about earlier will read the acual temperature the sensor is reading, mine said something like 120 degrees so i knew it must be wrong. dried the motor out and it now works fine again.
Now before you try to remover the motor from the pump please read my Roof problem post and dont doo what i did and try to remove the motor from the pump in the boot, it makes a right mess, hydrolic fluid everywhere. I would segest you remove the whole assembly from the car.
Now that might sound scary but its easier than it sounds. there is a you tube video https://www.youtube.com/watch?v=Qqg9c4fR0_c&t=57s
the guy explains how to remove the assembly and replace it with a new one. You just need to remove it and one its out on a bench or table hold it with the motor pointing up and the fluid reservoir at the bottom then undo the to retaining allen key of star key bolts that hold the motor to the pump, becareful though as when you pull them apart the seal will open and the fluid will leak out a bit ( try to keep the pump up right with the reservoir at the bottom) Watch out for the coupler dont let it drop out or the pins will fall out, it goes between the motor and the pump.
Once the motor is out you can remove the 2 off long bolts that hole the cover on. remove them and the cover will pull off. There may be water in there, there was on mine. when its apart you can either leave it to dry in the air a couple of days or gently use a hair drier to dry it out, not too much heat make sure to dry the electronic partsd at the bottom of the motor as that where the sensor is. the sensor actually monitors the motor temperature and not the fluid but reports back to the car as hydrolic temp . You can then clean the rust off the outside of the case and maybe put a dab of grease on the end of the shaft that goes in the housing ( Case) and reassemble it.
While it out on the bench try it with 12volts ( I used a battery charger) to see if it runs, if it runs nice and smooth then its fine and will not need to be replaced. you can also measure the resistance of the sensor. if there is no resistance then the sensor is broken.
The Motor cables should be in one plug connector with 4 wires 2 purple these are small wires and are the sensor the other 2 are larger wires and one is red 12V DC and the other is Black 0V DC or ground. use this red and blck to run the motor.
Hope this helps