warning sounder alarm horn stopped working

[rich222]

The warning buzzer seems very intermittant on the remote. Sometimes it warbles correctly when the key is turned to on, sometimes it just does a single fading beep and most of the time it does nothing.


I tested out the over temp alarm by grounding one of the temp switches. Nothing either.


New sounders seem expensive (it's for a boat so obviously has the boat premium!) when you can by piezo alarm sounders for £2.


Looking at the one I have in the OMC remote, it has a ground and 2 terminals. I assume one is for ignition on and should produce a beeping (intermittant) sound and the other (wired to the temp and other alarms) will produce a constant tone?


Is that correct, normal operation?


I'm thinking I will just replace with two peizo sounders, one that bleeps and one that's continuous.

[GuyC]

The Yanmar buzzer is £160!

On YBW a number of people have replaced buzzers with piezo ones.

If you have multiple circuits leading to one terminal I think you may need some diodes in the system so an alarm on one doesn't trigger warning lights on the other circuits.

[rich222]

Originally Posted by GuyC

The Yanmar buzzer is £160!

On YBW a number of people have replaced buzzers with piezo ones.

If you have multiple circuits leading to one terminal I think you may need some diodes in the system so an alarm on one doesn't trigger warning lights on the other circuits.

Yes, its daylight robbery! Wouldn't mind paying 10x the cost of a piezo if it was going to last but this one must be on it's last legs.


Looking into mine a bit more and trying to follow the almost useless service manual (wiring diagrams with nothing labelled...?).


The 'horn' has three terminals. Ground, +12v from the keyswitch and an alarm wire. The alarm wire goes to ground to signal alarm condition.



When the key goes to on, the sounder should do one fading beep.


Grounding the alarm wire should make it sound continously.


The VRO pump and oil tank sensor take care of making the pulsed alarm sounds themselves by pulsing the alarm wire to ground.


I have heard some outboards issue an alarm when the ignition goes on prior to starting and then going off when the engine actually starts but I don't think the one in the old OMC control does this. It just does a power on beep.

[rich222]

Had a look at the unit from the OMC remote. It's defo shot.


I cracked it open and the piezo disk has detached from the metal plate.


I'm just going to put in the tiny (and really LOUD) replacement I got for £1.50 (see top of pic)



If I really feel like it, I add a test button.