Intermittent start?

Vauxhall combo van 03 reg. Last year while driving noticed speedometer fuel indicator and rev counter would all stop working but van engine did not cut out. If I stop the van and turn off engine at this point engine will not start. Someitmes the speedo etc would just start working while driving Problem disappeared for a while but has come back and I can now hear a click when I return ignition key to off position seems to be from passenger side behind facia....previously engine would initially start for all of 3 seconds and then cuts out....now it is not starting at all... turns over ok and sometimes if left for a day or so it will start but not at the moment refusing to start.