I've used Garmin dashboard navigation systems for years. I've had my 2013 Expedition for about 2 months now and randomly loose satellite reception in the early evening. I've tried several Garmins and experienced the same problems so I know it's not the GPS itself. What I recently determined is that it is result of some kind of interference when the engine is running. As soon as I turn the engine off I immediately get satellite reception again. I don't have any problems during the day but starting around 7 in the evening the problems begin. There is a way to display the dozen or so satellites used by GPS systems and when it acts up there is little or not satellite signal. When I turn off the engine they come back strong. Anyone else experienced this or have a clue about what is going on??? Thanks!