With either side lights or headlights on the instrument panel light will brighten and then dim again. I know the panel light dims when you put the lights on. I can't tell if the headlights go off when the instrument panel gets brighter. This started a couple of weeks ago as a one off but today it happened a number of times on a longer journey.
As a sidenote the headlight alignment motor failed this week, the garage have disconnected it until the replacement arrives. Not sure if this is connected.
Any ideas?