[Geoff Kingston]

Is it not a case that the limit switches are fitted to minimise injury if you or your child has an arm, hand of fingers out of the window when they are powering up. If they are playing up the system can be made to work without them all it requires to counter that retrograde mod is basic observation watch and listen and when the window is shut release the switch.
I have never had the doors apart on my 411 and despite 12 years plus off the road the windows work perfectly. On my 603 the drivers side works OK the passengers side not at all, it does not help that the wire colours do not match the wiring diagram, Greg Lowe however tells me the best way to get the passenger side working is to take the power feed direct as the way Bristol did it there is too much power drop off on the passengers side especially if the glass is a bit tight in the frame.
At the moment am struggling with the electric windows on a 1972 Rolls Royce Silver Shadow LWB and most of the problems are simply down to corroded connections on the wiring systems in the doors.
The 603 window motors by the way are off the series 3 Jaguar xj6 so at the moment are still not too difficult to find, not sure what's in the earlier cars though.