View Full Version : Buzzer Alarm problem or not?

08-04-2013, 03:17 PM
1987 Tri Star buzzer alarm goes off when temp. gauge hits 180, goes away at 1\4 throttle. I do not think 180 is to hot or so I have been told . Mastercraft tech told me in boats that old they would just disconnect alarm and use gauges. I have replaced themostat,water pump,heat sensor I even moved themostat up 10 degrees still get alarm at 190. Any thoughts

08-04-2013, 03:52 PM
That buzzer is triggered by two things: oil pressure (lack thereof) or engine temp (too hot). What does your oil pressure gauge read when the alarm goes off?

The pressure senders are known to fail after a long life, and maybe yours is on the way out. They're cheap... a good project for the off-season.

PS: A bad ground can also screw with your gauge readings and trigger the buzzer even when there is not actually a problem. Does your voltage/oil/temp gauge change when you turn on a blower or a radio?

08-04-2013, 04:18 PM
Gauges jump slightly, but alarm seems to be working in conjuction with temp. gauge, when temp. hits 185 190 and alarm starts I just back off and run at idle for less than 5min. temp. drops back down to 170ish alarm goes away oil,batt. all good

08-04-2013, 04:24 PM
Do you happen to know which thermostat you are running? 190 degrees seems pretty toasty for these boats.

My 1987 351 lives at 160 degrees.

In this thread (http://www.mastercraft.com/teamtalk/showthread.php?t=30244) it's said that the alarm will sound at 200 degrees. As mentioned in that thread, if you're getting that hot be sure to let the engine idle before shutting down.

08-04-2013, 04:31 PM
Thanks for input need all the help I can get will replace sending unit and pull dash to check grounds was thinking about replacing oil,temp.,volt gauges but they seem to be working just fine. STUMPED ?

08-04-2013, 04:41 PM
Old one was 145 replaced with 160 ,alarm starts 180ish temp. has never been above 200 slighty below.