So I went to the lake yesterday was out for about two hours and while in the no wake zone the warning horn came on, a constant beep. The strange thing is I have installed the Mercury smartcraft gauge sc100 and that gauge indacaited that there was no problem . The warning horn, the one that is included on the ignition harness was the one going off and the SC100 showed the temp was well within range, water pressure was good, and did not sound an alarm. I check the oil on both the engine and the remote tank. Also the Smartcraft Guardian system never engaged and on the way back to the dock I had it up to about 4300 RMP with no problem. Has any body else encountered this before or maybe has an idea as to what it could be? I took it in too the dealer should here something back back in a few months . I should also mention the the motor has less than 15 hours on the brand new 2006 motor.