Vectra started ok then stalled at junction and failed to restart! Checked voltage to heater plugs and the heater plugs themselves found two down so replaced with new! Failed to start again so checked that the injectors were working, they were ok. Rechecked voltage to heater plugs - NO Voltage??. Is the comman rail protected by a relay or fuse? could this have blown? No idea which relay does feed the comman rail or why there should be no voltage found at the heater plugs? Also when ignition is turned on the glowplug indicator light doesnt light up on test? Any ideas?