Engine Alarm Buzzer

[Duke 7184]

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

[hellosailor]

Duke, you're right about that, I was thinking "buzzer" and forgetting it is more like a noisy capacitor. 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.

[Kiltmadoc]

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.

[hellosailor]

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.

[Kiltmadoc]

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.

[hellosailor]

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.

[Undadar]

Originally Posted by Kiltmadoc

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).