my mates 2000 astra sxi is messing about. when he puts the tail lights on the high level brake light comes on dimmly. whe he presses the brake pedal he has no brake lights at all. he also has a problem with the stereo. the permanent feed drops to 2 volts when he turns the radio on, so doesn,t store the stations. i'm thinking an earth fault somewhere. Anyone seen this before. I'm going to look at it this weekend.