I had same problem on my 30' 79 Hunter
I had the same problem. I replaced the buzzer which is sold as a Yamar part. The part is the buzzer, screw on ring and pig tails. I was surprized at how easy the replacement went. I unscrewed the pannel, unplugged the pig tail, and unscrewed the ring. replacement went in reverse order. Time- 10-20 minutes top. Price was around $125.00-$150.00 which I thought was way over the top. I am not sure about the price but I remember it was expensive.I spent the money as I have had my lights lit up and did not know it. $150 is less expensive than a new engine or engine repair.I have also replaced the sending switch for the hot water at $10.Good luckIans/v Meant to Be