Thank you both,
It is not the fuse. In fact, I've taken the regulator out and the motor is working fine too. Good news.
But, Stanleystreamer, I know exactly what you mean. As I pulled the mechanism out from the hole in the door, I thought "I'm going to have a job getting this back in", because it is unscrewed blind.
Would you both have a look at the attached images and tell me if anything looks broken? All the pivots are greased and moving, and I can't see anything amiss. The half cog wheel didn't come out with the rest of the mechanism and where I've circled in orange it looks to me like some weld has broken. Is this correct and should this cog be connected to the main mechanism?
When I unscrewed the regulator from the door, the bolts were indeed very loose. If the mechanism looks unbroken, maybe they were just loose and something has disconnected?
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