I am once again soliciting the help of my fellow Four Winns boating bretheren. I installed a new dual horn on my Vista a couple weeks ago. I was sick and tired of the "sick goose" sounding factory horn that Four Winns installed (and besides, it quit working) so I bought a new one from West Marine. Really simple to install, right? Cut off the old, connect the new. Easy done. The new horn works and sounds great..........when it works.

I did have to go from the 3 amp fuse that was in it to a 15 amp fuse as recommended by the manufacturer.
Here's the issue. The horn will work while underway or at idle speed, however when the engine is turned off and I am sitting at anchor, the horn doesn't work. It will work while plugged in at the dock and the engine is off. When I push the horn switch while at anchor, I can hear a "popping" or "cracking" sound in the stereo speakers, but the horn won't blow (hate it when that happens).

I will even occasionly get a real real quick horn sound but not a full fledged blast.
So what's the "dealio"? Is it simply that the battery is not supplying enough amps? Am I just an idiot here? Does this new horn draw too many amps? Am I using words that make absolutely zero electrical sense?