Alarm going off without even starting engine

[theginns]

Quick one here. When I started my boat (1977 85 Johnson) the alarm started blaring from within the shift box. I am assuming that the alarm blaring is the overheating alarm. However, the alarm started as soon as I turned the key without starting the engine. I am getting plenty of water coming out of the engine, and besides It was blaring before the engine was even started. After about an hour of agonizing sound, I turned the key ever so slightly back toward the off position just enough to keep the engine running, and then the alarm went off. But everytime I start it now, I hear that obnoxious sound until I get it running, then turn the key back a hair. This has never happend before. Anyone have a clue? Shorting out? Thanks.

 

[WillyBWright]

Re: Alarm going off without even starting engine

Either the overheat warning system has a short in a wire someplace between the sensor and the horn (most likely), you have a shorted sensor (rare), or you have a shorted warning horn (somewhat common). That motor originally came with what I'll call a Buzzer horn. It's only a horn and I've never heard of one of these shorting and sounding by themselves. The newer alarms I'll call Tweeters. They have circuitry inside that checks the warning system and lets you know it's functioning by giving a few beeps every time you turn the key. Those are the ones that will sound if they fail. The buzzers usually just up and fail...you'll never hear a sound.