# Engine Alarm Buzzer



## Duke 7184 (Mar 12, 2006)

I have a 1982 Morgan 321 powered with a YANMAR 3GMD motor. I need to find a repalacement for the engine alarm buzzer. So far I haven't been able to come up with a part mumber. The current buzzer is manufactured by Hitachi and is wired for multipal inputs: low oil pressure, high water temp. My owner/operator manual only indictes that it is a "B-Type" alarm panel. 

Any assistance you can give me will be appreciated.

Duke


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## trantor12020 (Mar 11, 2006)

what's wrong with your stock buzzer? does it use all 3 inputs or just 2?


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## Duke 7184 (Mar 12, 2006)

All three inputs are used. I failed to mention the charger is also attached to an input.
The buzzer has no audio even with 12 vdc connected directly across the input(s). I suspect that the piezoelectric crystal is bad. The buzzer is in a sealed housing so checking further for defective componerts - diodes, etc. - is imposible.


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## neilchristophers (Sep 14, 2006)

VDO makes a multi input buzzer that fits in the dash 2in hole but if yours is mounted behind the dash there is no reason why you carn't use two seperate alarms [alot cheeper] Neil..


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## trantor12020 (Mar 11, 2006)

Duke7184, your buzzer model is WI1-05. Its one input and 3 output (negative as return) via 3 diodes. If the other two alarm works, then its probable the 3rd diode is faulty. You could wire two diodes to one of the working output thus making it as 2 circuit. That should solve your problem. When activated, the positive passes through the buzzer diode, then through to 1 of the new diodes to say Oil Pressure switch or Sail Drive Unit switch then to ground (negative). The buzzer maybe just alittle softer as there'll be 1.2V drop across the series diodes but I guess it won't affect much. The Hitachi buzzer doesn't come cheap.


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## hellosailor (Apr 11, 2006)

Sounds like you could buy one loud buzzer for about five bucks from any electronics place and add three diodes for about 25c each. Or, just buy three piezo buzzers and separate the circuits so each has a different sound, too.

www.allelectronics.com one of many surplus & parts houses with this stuff.


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## Duke 7184 (Mar 12, 2006)

trantor, Thanks for the information. I will do a little research and see what I can find where and for how much. If you know of some places that deal in this type of YANMAR/ Hitachi components please pass them along. The diode "OR" circuit you discribe could be made to work even if only one of the alarm circuits were still functioning. However, none of the alarm circuits are working. That is why I think the piezo is bad. 

hellosailor, I appreciate the input. I have noted the email address you provided and will check them out should I decide to go that route.

Duke


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## hellosailor (Apr 11, 2006)

Duke, before you assume the piezo is bad? Use a multimeter or test light to check on it. It is also possible (I think) that if one diode shorted, instead of failing open, it would simply ground the other signals and prevent the piezo from sounding. (Which is why three separate circuits could be good, even though three times more parts could just give you three times more stuff to fail.<G>)


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## Duke 7184 (Mar 12, 2006)

helosailor, as I have already stated, the diodes are encapsulated in a module with the piezo. Keeping it simple: I removed the Acoustical Warning Alarm Assembly (AWAA) from the cockpit engine control panel; thus, totally isolating it from the input sensors. I connected +12VDC to the appropiate termnal on the AWAA. Then, one at a time, I connected each alarm point/terminal to ground (the negative side of the battery in this case). The piezo never sounded. It may be the piezo is not bad - it could be a broken wire - , but without breaking open the AWAA module there really isn't a way for me to tell. At this time I don't want to smash the module. I have remounted it mechanically to fill the hole in the control panel to keep rain out. 
Duke


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## hellosailor (Apr 11, 2006)

Duke, actually you said "The buzzer is in a sealed housing " and a sealed housing can usually still be cut open. Encapsulated is indeed another matter.<G>

"but without breaking open the AWAA module there really isn't a way for me to tell." There is a way to check, use a DMM or ohmmeter to test the circuit. If the diodes are all functioning, the circuit will show near zero resistance one way, and near infinite resistance with the opposite polarity.

If the resistance is the same (near zero) both ways, you have a shorted diode. You should also be able to test across each diode lead to the other two, which will tell you which one has failed--if it is a diode failure.

If it is a diode failure, a dremel tool can solve the encapsulation problem if you really want to repair them.


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## Duke 7184 (Mar 12, 2006)

hellosailor, Even if there was a shorted diode,checking the alarm circuits individually (with all other diodes disconnected at the end opposit the piezo) the buzzer should sound for any good circuit(s). Also, you may want to check piezo theory before you check for a bad diode that is in series with one. It has been almost 40 years since I have actually had piezo theory, but I don't think you can read a resistance across one. Again, I may be mistaken, but I think it would read similar to a capicator or just an open circuit.
Duke


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## hellosailor (Apr 11, 2006)

Duke, you're right about that, I was thinking "buzzer" and forgetting it is more like a noisy capacitor.<G> The only one I had at hand to check is rated 3-16VDC, so it squeals when my DMM tests it with correct polarity and shows "overrange" on all scales in all cases anyhow.


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## Kiltmadoc (Nov 10, 2009)

I know, old thread resurrected here. But, this is the only discussion I can find on this part that i am in great need of acquiring. Does anyone know where I can find a used hitachi Wi1-05 buzzer for less than $180? That is the current going rate. Or, better yet, anyone figure out how to break into the darned housing in order to fix the stupid buzzer? Mine is rattling around in the housing like a walnut in a plastic easter egg.


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## hellosailor (Apr 11, 2006)

Is the buzzer connected by a 2-terminal connector? Or one wire plus a ground? If so, you can check to see if it is "just" being sent 12v to activate it, and replace it with any buzzer or 12 volt relay to drive another device.


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## Kiltmadoc (Nov 10, 2009)

The buzzer has 5 pins in the back. I understand that the buzzer goes off not just for low oil pressure, but several other things as well. I wish I could just do what you say, but it's more complicated. Has anyone cut the housing open to fix it themselves? I was thinking a few minutes with a dremel tool followed by some JB weld to put it back together.


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## hellosailor (Apr 11, 2006)

Five pins, then yes it is doing more. I've seen some Japanese relay components built by the "GE School of Engineering" i.e. GE used to build products where the case very cleverly wasn't just a case, but held internals in position, sometimes spring loaded. 

So if you try the Dremel route, and can't see any seams to pry or pick at, beware "sproing!" when you open it. Somewhere in there...the noise making part should come down to a piezo chip, or a buzzer, or something that can be replaced. At $180 I'd try to find out more first.


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## Undadar (Mar 24, 2011)

Kiltmadoc said:


> The buzzer has 5 pins in the back. I understand that the buzzer goes off not just for low oil pressure, but several other things as well.


That might be the problem. Typically you want the buzzer to come on when there is a problem - not go off. 

No idea if they have it but McMaster-Carr might be a place to look (McMaster-Carr).


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## douginnanaimo (Aug 17, 2016)

I have Yanmar 2GM 13 in a Tanzer 8.5 and similar problem with the alarm. I removed the alarm unit Hitachi and priced is $285 in Canada!!!
not happy with that I cut mine open and then figured out how to open without surgery. 

on the front face- that which is exposed while in the panel pic 1- open the seam on the face. pry with knife and push on connector end and it will come out.. Mine had insect nest so malfunctioned!

I have new piezo alarm however original has three wires- red, blue, black and replacement has only two. I will have to find an electronics guy to map it out. pic 2


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## Mike_NC (Jan 22, 2016)

I just left the buzzer in place and did away with it. I replaced the bulbs with LEDs and then put 12V piezo electric buzzers in parallel with the LEDs. On my panel there are three lights (oil, charge, temp) and the buzzer is designed to go off on oil and temp as well. I don't remember the wiring but it is best to put the buzzers in parallel with the lights because the existing buzzer inputs will backfeed on the ground. My buzzers are secured behind the panel so you can't actually see them. I think the ones I bought were 75db and they are loud enough.

Do a search on Amazon and ebay for"12V panel alarm" and "12v alarm buzzer" or something like that and you will see tons. Just need to make sure the light is the right diameter to fit in the hole. You can buy everything for less than $20, you will need 3 lights and two buzzers (I bought extras). It is all Chinese made but I can replace it over 10 times for the cost of the OEM buzzer. You can buy the lights with an integral buzzer but I think they were too big to fit in hole. Mine has worked for over a year.


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