Thanks,,,a good evening was had.
The weathertried to do a spoiler...but I'd done the BBQ before that drop of rain came and drove us indoors.
Just a slight muzzy head this morning...quickly fixed with a tea.
A tip, when testing the voltage load up the circuit while doing so. I use an 18w bulb with some wires attached. You don't even need a volt meter just touch the wires from the bulb across the circuit, if it doesn't light up brightly you have problem with the circuit somewhere. If you feel you need to know the voltage only do so with the bulb attached. Next after checking for obvious possible corrosion points is to go back along connection points to breakdown which part of the wiring has the problem. The problem with using a voltmeter is they require such low current to operate (very high impedance) even if the wiring is only connected by totally corroded through copper the full battery voltage will still be shown! only a completely open circuit will indicate 0 volts. This results in much wasted time as you think the problem lies elsewhere.