335D '57 Faulty light failure warnings

Hello, I have a '57 335D which has shown up 6 warnings including OSF indicator, OSF headlight, NSR fog light, ALL side running lights, NSR brake lights failure. When checked, the bulbs seem fine (not checked the brake light bulb as this could be an issue as it often needs removing and cleaning before replacing again to resolve same fault - no water ingress evident).

Any ideas how the sensor monitors the different areas and why I see so many issues at once ? Thanks, Darren

check your earths the short out i had te fix a earth onto my lights and it fixed the fault