I have this black device near my DC Panel, that I think is my engine alarm? Anyways, when the key is switched to ON, it emits a moderate whining sound. It continues when the engine is running. I don’t the the sound is an ‘alarm’ as I can’t hear it from the cockpit. When I tap it firmly, the sound stutters with each tap.Can anybody confirm that this is the engine alarm, and what is causing the noise? Thank you.
Darren Plumbe
N22 #20
Madeline Grace
PYC Brighton ON
Darren,
The device in your photo appears to be the engine alarm. If you have a Westerbeke engine, It has three functions;
Key alert - Lets you know if the engine key is inserted and turned to the “on” position. The alarm should go off once the engine is running. The main function of the alarm in this case is to remind you to remove the key once you have shut down the engine. Otherwise, you can quickly drain your batteries.
Water temperature alarm - Will sound an alarm if your engine water temperature is too high,
Oil Pressure Alarm - Will. sound an alarm if your oil pressure is too low.
Attached are some pages from the Westerbeke parts manual that show the buzzer and associated alarms.
I hope this helps,
Mike
Mariposa
NS30U. Hull#272
Dutch Harbor, RI
The alarm sounds when you turn on the key, but before the engine has started, because there is no oil pressure. Once engine starts and oil pressure builds, alarm will stop. If your alarm is not loud enough, check and clean the wires connections, could be they are corroded. But, first take a photo of of the back showing the wire positions so you know how to reconnect the wires correctly. My alarm has three wires attached. The wiring diagram Mike attached is different than mine.
Cleaning the contacts is an easy fix. Maybe you need to replace the alarm itself, but they are fairly inexpensive.
Don
Thanks for the insights. When the alarm is on, I can’t hear it from the cockpit. How loud should it be?
Darren Plumbe
N22 #20
Madeline Grace
Brighton ON
Thanks. I took a look at the back, and the connectors look good. Also, both my oil pressure and water temp gauges appear to be working fine. I will check the current and continuity when I have my multimeter with me. With only 2 wires, it seems to me that is should either read 0V (off) or 12v (on). Anything else would be whatever controls it.?.
Loud enough that you will hear an annoying sound when the engine is running. You can test the alarm itself by connecting it directly to one of your batteries to see if it is working okay.
Don
’87 NS30U #369 - Breezin’
Vancouver, BC
Darren,
My alarm makes a very high pitched sound that would not be audible when the engine is running if the water temperature or oil pressure sensor went off. Therefore, I am going to install a louder buzzer (85 db) that I recently purchased from Defender for around $20.
FYI,
Mike
Hi Darren,
I think Don might be right. The alarm is very loud and audible from the cockpit if the engine temperature is too high. Probably a wiring issue.
Doug
N26 #2
Top Cat
Brighton, Ont.
Everyone,
All good insights. Now I am going to attach my buzzer to a 12 VDC power supply and see if the sound notably increases. I have not had a high temperature or low oil pressure warning so I do not know what it would sound like in those conditions.
Regards,
Mike
Yes absolutely replace it and save the old one for a backup.
When in doubt throw it out. For $20 it’s a no brainer.
Be sure the new alarm works as described in this post.
Brian Cayer
Spirit~Wind
N30U 419
Westbrook, Ct.
All great information. And a special shout out to Doug… Madeline Grace’s former Skipper. And if I recall correctly, you probably had it ‘tested’ prior to upgrading the cooling system. 
I will connect it directly to 12v DC and report back. However, it is currently ‘wining’, so it must be getting some power or a stray current from somewhere.
Darren Plumbe
N22 #20
Madeline Grace
Brighton, ON
It should be fairly loud when you turn the key to “on” position without starting the engine, because there is no oil pressure. Either the alarm itself is old and damaged, or the connections are corroded or possibly one connector wire is broken. But removing it and connecting directly to 12vdc battery will at least tell you if it works.
Don
Are three 3 terminals on the back of the alarm? The schematic only shows two terminals also. If there are 2 wires on one of the terminals someone needed a key on 12 volts source. One of the wires to the alarm should be key on 12V and the other wire goes to the two warning switches that provide the ground to turn the alarm on.
My alarm is loud enough with the engine running to not ignore.
Bill Mortensen
NS30U #335
Summer Song
Noank, CT
