My friend's explorer is doing this wierd thing where the "FUEL RESET" light on the gauge cluster comes on, but only when the drivers-side door is open. Disappears when the door is closed. I think it's some kinda electrical problem. Anyone have any ideas? Also, does anyone know if this particular vehicle incorporates a vehicle speed sensor in both the tranny AND rear diff? Because his speedometer is not functioning as well. Thanx in advance.