3 times I've noticed this happen recently, I've been driving between 60 and 70mph when the dials on the dash go down to zero and the lights on the dash come on as if I'd just turned the ignition on. The car doesn't lose power or speed, the radio still works the headlights are still on and the heaters are still blowing. This ishappens in no more than a second. Just long enough to get my attention.