2005 280DA with smart craft. Keep getting the alarm of lost comm with tach and speed going to zero.Boat still runs with alarm going off constantly. Shut down and restart helps for awhile but alarm returns. Checked connection at engine and still get the alarm. Completely random as can go hours with no alarm and then get the alarm constantly.Have had the problem for years,but recently it has gotten to be a real issue. When the lost comm happens the engine surges down and back to normal. Any help appreciated.