Failed mot - no hazards or sidelights when ignition off. Checked AD for wiring diagram (waste of time) so started at fuse box with a multi-meter.

After an embarassingly long time I traced it to the front battery (out of the two under the seat) being completely buggered. There is a big split charge relay under the seat which connects the two together when the ignition is on but when turned off - even after running for 30 minutes - the front battery dropped back to 4 Volts!

A pair of batteries and away it went