I have bought a solenoid activated valve for the gas bottle in our caravan.
It works by energising one coil to open it and one to close it. The coils do
not have to stay energised. The original plan was to use a (on)-off-(on)
rocker switch to control it, but I am feeling a bit more adventurous and
would like to incorporate a warning light to show that the valve is open. I
figure that the way to do this is to build a simple circuit that latches on
or off according to which way the rocker switch is pressed. This is where I
require some assistance. Although I figure it is easy to achieve, it is
beyond my knowledge. I would appreciate any help that you can offer.

Going beyond the simple warning light, it could be developed further. he
light could be powered by its own battery, so that if the caravan is
disconnected from the car with the gas valve open, the light stays on. Maybe
it could be possible to incorporate a buzzer to warn that the car battery is
disconnected but the valve is still open? The valve has to operate from the
car battery because it is 12volts.

Like I said, I guess this is simple to achieve but I don't know where to
look. I can build the circuit but not design it. Thanks for any help or
suggestions.

Jo