intermittent electrical fault

we have an Autosleeper Malvern on a Mercedes Sprinter Automatic. Recently, while driving we get warning lights saying the handbrake is on, sometimes it says we do not have our seatbelts on (which we do). When we get this we have no indicators or windscreen wipers. Going over a bump sometimes reset this, but not always. Has anyone else had similar problems??

Maybe check with a Mercedes servicing company. We’ve gone their for Sprint errors in the past.