Sorry, I asked the 機器廠 to fix it. They told me option one is take off the lubricate detector to stop the alarm, but you will have no more alert function when you lack of lubricate next time! Option two is change this detector (But it links with the lubricate tank and you have to change it all together). I took option 2 at the end, and the 機器廠 charged me around HKD 1,200 for my Mercury 125 hp. Your guessing (Shortage of circuit) can be one of the reason! Lets pass it to 機器廠 to make sure! Sorry about this is my only little experience! May some C 兄 give you better idea! Good luck!