i think you are right guys , when I tried it today it only stops now every now and then , it seems like it is struggling to open , so I sprayed lots of grease around the runners etc and it makes it better , il see how it goes

hi guys update on my problem , after changing all the wires in the loom , it was still slow and still stopped every other time , so I changed the motor and its now perfect , thanks for the help everyone

forgot to mention , I stripped my mirror down to the motor and opened it up , there is a little cog that's is worn very bad inside