Holdmybeer,

Wanted to follow up with you now that I was able to get a test run in this past weekend, thanks for your input, issue resolved. Here is what I found. All connections at buss bar were solid. Checked all other wiring under dash and at battery (all good). Removed amp mounding board to see amp connection/wiring that were hidden. When looking I noticed the butt splice connectors for the grounds coming from 2 of my amps were crimped to much (little tear) which exposed the metal inside them. Both grounds were close to each other so thinking they were wiggling when in motion which was just enough to cause one amp to go into protection mode. Fixed connections and had no issues with the sub amp going into protection mode this weekend. Also hit the horn button while on the lake (first time ever hearing the horn). That was extremely like the alarm/noise I was trying to describe, just not near as loud as the horn itself, but a faint replication of the horn so think you were correct that the faulty ground might have been affecting the horn as well. Appreciate your response, as it assisted in determining a place to start trouble shooting!