2004 90 hp Merc Outboard, I have a temp siren that wont shut off is there a reset I dont think I have a heat problem , staedy water stream and good pressure on gauge with boat on the trailer key on siren wont shut off ?
It could be a faulty warning module or sensor. I had problems with the warning buzzer sounding all the time for no reason. Turned out I had a bad module and it was a common failure. Installed a new one and it last about one boating season said screw it and unhooked the buzzer. I don't recommend you do that.
The overheat switch/sender could be bad or the tan/blue wire could be worn through and shorted to the block. Check, test or just replace before you buy a new expensive module.