Couldn't wait until Friday so went out there after Men's Shed.
Straight forward tracing the switch wiring. Basically two switches in one, with the left side being for the item being turned on, and the right side supplying power to both lights through the two separate earth connections (whatever).
Nothing different to how I connected it yesterday, except today it decided to work, and then failed, blowing two fuses! After replacing the fuses I discovered the earth terminal for the large light on the first switch is not attached firmly and can disconnect itself with the slightest movement, somehow disrupting everything else.
I am still somewhat wary that this is not the whole story, but with the switch unit hanging down by the wires from the fuse block all switches and lights (and ignition switch
Pierre
) functioned as they should.
I was only outside for about half an hour by which time I was wet with perspiration and came back inside, hoping I can count this as a win situation.
Once inside I duly drew up a wiring diagram (with a sort of explanation) in case anybody else should happen to buy some of these Jaycar switches. Big question now is,
Will it work tomorrow?