VP D2-55 engine alarm question

[Tintin]

I have not read the manual for that particular engine as all diesel engines are basically the same, I am using my past experience as a marine fitter maintaining / repairing many commercial craft. If you read the second part of the last sentence that is what I have suggested. Jim

How very dare you try to offer help and advice VicS.

 

[MagicalArmchair]

So now you need to prove if the problem is a faulty buzzer unit or a faulty logic block. Remove the two wires from the buzzer and connect the buzzer directly to a 12V supply, make sure the polarity is correct. (Might be easier to remove the buzzer unit from the panel) If no sound from buzzer then it is obviously kaput. If the buzzer sounds correctly then the problem is likely in the logic block that houses the warning lights.

Volvo prices for the spares are not very nice!! If it is the buzzer then you can source an identical item online by using the part number or alternatively buy a 12V buzzer/alarm sounder and wire it in place of the existing. If it is the logic module then you will likely have to pay Volvo's exorbitant price for a replacement.

The logic module is part of the engine control panel and it contains the warning lights. It is a sealed unit with a short wiring harness coming from it.
It will be obvious when you remove the engine panel from it's mounting position.

Thank you. I have a feeling at least one of the bulbs has blown too, so I will take a look at that at the same time as it have it all apart.

 

[MagicalArmchair]

A quick update on this one. I've taken the panel off and checked the buzzer, and it does work when wired up to 12V (it's quite loud! Nearly woke the kids up when I was testing it on the dining room table!). I've put it all back together so I could go for a sail, I've now recieved the bulbs so when I get a chance this week I'll take it all apart again and replace the two blown bulbs. Could it be the buzzer test doesn't work if a bulb is out? Perhaps the test is wired in series? It's that or it's the logic block (one of these: Volvo Penta 873 737 Electronic Unit , a cool £250 ) - Although an LED version costs the same - and would avoid that awkward "oops, left engine switched on, now the batteries are flat" scenario ... Electronic Alarm Unit control Module Volvo Penta 873737 new number 22354203

 

[MagicalArmchair]

After replacing all four bulbs, the alarm still does not work, and two lights are still out.

I guess the next step is replacing that logic block? Anything I can do to fix the existing one?

 

[MagicalArmchair]

The logic module is part of the engine control panel and it contains the warning lights. It is a sealed unit with a short wiring harness coming from it.
It will be obvious when you remove the engine panel from it's mounting position.

To finish this one off, in case anyone else comes this way with the same issue, I purchased the frighteningly expensive logic block and swapped it out and presto! All works! So credit to Cris and Vic for putting me on the right track.