Re: 90 hp mercury outboard on 2005 sun tracker
Under the oil tank you should find two blue wires coming from the oil level switch, unplug either one. If this stops the horn then you need a new oil tank assy as you cannot repair the float inside. The adhesive holding the magnet to the bottom of the float has failed, allowing the magnet to fall onto the switch, triggering the alarm as if low on oil.