louder warning buzzer on 2009 Bav 34

[Bobb]

Hearing is going and i can barely note the two-beep starting signal, so i'm trying to install an extra-loud external beeper.

Wiring for the MDI shows position 2-3 from the MDI going to the buzzer on the tach assembly. The only wiring diagram i can find doesn't show polarity, but i assume one as pos and one neg (grey, grey/black).  But even when i disconnect the 2-wire harness  from the MDI to the tach unit, the beeper still beeps! Shouldn't that come from the MDI? It's as though the signal is totally internal to the instrument/tach unit.

anyone done this successfully?

[SYJetzt]

Don't know from where you got your pin positions. Take a close look to the service-manual which you find on this site https://bavariayacht.org/downloads/engine/Volvo%20Penta%20Electrical%20System%20D1%20D2%207748428.pdf
On page 42 you have an interface description for the button panel, where the buzzer should be wired on pin 6(+) and pin 4(-). Would suggest to wire a new buzzer over a relay, as the current draw of a bigger buzzer is maybe too high for the mdi to drive directly.

[Bobb]

Thanks! I'll go back and check .. either i was reading the wrong page or have a different print-out.

Bob

[Rufduck]

Hello,   New to the site but old to MDI woes.
Have two D1-30B engines and the MDI boxes are a pain in both.
Thank you for the hints re a louder warning buzzer and specifically adding a relay to drive the buzzer.   
The MDIs are now around $1000 US here in Seattle if you can find one (they are available now from at least one source).
Has anyone simply eliminated the VP MDI setup and replaced it wholesale with a conventional hard wired system?   I’ve reached that point after an unintended shutdown nearly put me aground.   Curious just exactly what parts are needed.
Thanks again for another informative site.
Cheers, Martyn Adams