Smart Craft alarms w/ ignition switch off

Discussion in 'Electronics Q&A' started by Seabbatical, Aug 16, 2022.

  1. Seabbatical

    Seabbatical New Member

    Dec 11, 2007
    Erie, PA
    2006 27' Sea Ray 270 Amberjack, Raymarine C70, Northstar NS100SS
    Mercruiser 350 MAG Horizon w/ Bravo III drive
    Hello folks,
    My boat is a 2006 Sea Ray 270 Amberjack equipped with a Mercruiser 350 MAG MPI Horizon, which was purchased new.
    While recently running on plane at an RMP of around 3,900, the Mercury Smart Craft audio alarm sounded. It is was not a periodic beep, but a continuous ear splitting alarm. I slowed down to idle speed and peered into the engine compartment fully expecting to see the gear lube resouvir empty, which had precipitated an alarm a week early (the reason for that may be the subject of a separate post). I was surprised to see that it was full. Upon returning to the helm I was further surprised that there was no visual error message on the Smart Craft gauge, as there had been in the past when the audio alarm sounded. The next surprise came when the ignition switch was turned off and the alarm continued to sound. This also had never happened in the past when the audio alarm sounded, and was really baffling to me. I checked everything that is listed in the Smart Craft User's Manual that can cause an alarm that I was able to, and nothing seemed amiss, and the boat seemed to be running well.
    It was not until I returned to the dock and disconnected both batteries that the alarm was finally silenced. With both batteries disconnected and the shore power on, the audio alarm sounded. With battery #2 connected and battery #1 disconnected there was no alarm.
    It would be greatly appreciated if some of you very knowledgeable folks out there could provide some direction in tackling this issue. Unfortunately, it appears as if the bilge pump is also connected to battery #1.
    Another piece of information that may shed some light on the issue is that every since the boat was new, frequently when the boat came off of a wave and pounded, the Smart Craft alarm would chirp - just a single chirp.
    It seems to me that a key to determining the cause of the issue is that the alarm sounds even with the ignition key turned off. Does this mean that the issue is not with any of the sensors, but something else?
    I have obtained the schematic diagram for the Smart Craft system.
    There was a previous post regarding exactly the same issue, but the poster said that the problem had just gone away.

    Thanks in advance for any suggestions,
  2. Coz

    Coz Active Member

    Oct 9, 2018
    2008 Sundancer 310
    Merc Mag 350 DTS w/Bravo III
    Have you checked all your pump floats including the one by your shower box?

Share This Page

Show Sidebar