Inside the S3/4 fusebox there is an off white plug connector (flat rectangular shape) You disconect it and plug in the shorting plug (my name for it) and then go through the CAM reboot process.
The switch Simon is referring to disconnects the battery from the system (useful if you dont use the car everyday as battery will go flat). When you turn it back on by pushing the black piece back in, you need to reset using the drivers windo switch.
Not the same as clearing and rebooting the system, which MAY be what is needed for the S1 problem described. Your local Morgan garage should have a 2 page instruction plus the shorting plug in their workshop which explains the full procedure. I have my own which I keep in the car.
