Novice seeking help on this topic: The rev counter on my 2013 Sigma Supersport has become....lets call it 'sporadic'! The rev counter does nothing at startup, occasionally bursts into life with the needle moving freely round the counter then dies again. A few minutes later, it'll do the same. To my ill-informed mind, its behaving like there is a lose connection around somewhere and whilst I've had my head at all sorts of angles looking for something obvious under the dash and even in the engine bay, I've not spotted anything so would appreciate some guidance. I've read on the forum that the other instruments on the dash (temperature, fuel) might have a common earth but, again, not sure where I'm looking to check if that is lose (though, there are two black wires attached on loop connectors to the underside of the dash on the passenger side which look likely candidates - both are tightly attached). Its a standard Caterham rev counter. Hopefully that makes sense and there is a simple cure. I'd also be interested to know where the rev counter takes it reading from, is it off the ECU or a sensor on the engine? Might help me narrow my search down. Thanks