Had the same light and buzzer problems. The control panel for my 1GM is located in the cockpit and exposed to the weather. Pulled it apart and found quite a bit of corrosion, poor electrical connections (bad lugging and solder joints....solder joints?) Cleaned it all up and did it right (I'm a marine electrician of a retired US Navy variety) and voila! No more problems! I did check the wiring and sensors while I was at it as well. No probs on the engine side.