Any ideas what the sign "warning - 0 volts" indicates on the dash? It can't be cancelled. The rear fog light has also stuck on, although the button can still be depressed. Wondering whether the two are related.
I get this whenever I start the car but it only flashes up then goes away. I assumed it was a battery charge warning. Not sure that helps you much if yours stays permanently on.
Might be worth checking that the circuit board behind the switch is not earthing to the alloy dash pod. I made a little gasket out of a rubber glove to sit under mine. Also just check that the wiring on the two ribbon cables hasn't broken away.