hi everyone i need some help diagnosing this problem.just fitted new battery and plugs as required and couple of days later car just went dead at 50 to 60 mph.all instrument panel lit up,and engine stopped speedo went to zero before car stopped.all dash warning lights went off ,back to normal.put car into park and turned ignition on, then started car as normal.it has happened again once,two weeks later. any ideas please.i have checked integrity and tightness of topside earth connections.steve c.