Engine buzzer not sounding on start up

[Scorcher IV]

Hi all,

I believe there is a known problem with the control unit mounted to the rear of the Volvo Penta instrument panel. the buzzer on my Bavaria 37 (2006) is not sounding when starting the engine although it does work when using the test switch, the water temperature light is also not working but this may just be the bulb. Prior to purchasing a new unit  (cheapest found so far is £246) is there a way to check it. I removed and cleaned all the contacts but no joy.

[dawntreader]

Hi Scorcher,

I too have a B37 2006 but am puzzled by your note. I don't think the buzzer is meant to sound when starting - mine never has. The test switch position proves the buzzer would work and I understood it would only sound if a 'fault' condition occurs e.g. low oil pressure or overheating. 

[IslandAlchemy]

The buzzer doesn't sound when starting on the Volvo

[Scorcher IV]

It might be my mistake but there used to be a low tone from the buzzer (just audible) when starting and now nothing, I will replace the bulb next time I am at the boat. If I ground the water and oil connections on the engine will this give a fault condition to sound the buzzer?

[dawntreader]

These may be useful for you - an electrical schematic

[Scorcher IV]

Thanks for the schematics, I have ordered the bulbs and will earth out the sensors on the engine next time I get to the boat, just to make sure the alarm works as it should. Don't want to be trundling along thinking everything is ok and the alarms don't work and the first thing I know about it is a piston exiting stage left.

[dawntreader]

Wouldn't worry about the piston - you have 2 spare 

[Domi409]

On my similar boat, the buzzer does not sound when starting. One possible test is to start the engine, and you keep it on while going down in the cabin. Then, open the engine compartment and turn off the engine with the small lever on the left hand side of the engine. For a second or two, the buzzer will sound!

[Scorcher IV]

Been back to the boat and checked the unit by grounding the water temperature sensor and the alarm sounded, the bulb had blown as well so thankfully do not need to change the sealed control unit. It was my mistake over the buzzer sounding prior to start up, I always thought it was a safety feature that the alarm went off prior to starting to warn anyone who's working on the engine that it was about to turn over but not on Bavaria's.

[Sen Mora]

For me it is logical that with power on to the control panel every time the oil pressure is zero the buzzer sounds. Every time you start and shut the engine you know your buzzer works. It is like that on Yanmar powered ( my previous boat ), not sure how was it originally on my B41, because the electronic unit behaved very erratically ended not working at all. Also the FRP panel was broken in several places, did not have pressure&temp gauges. So I ended designing and building a new panel without the ridiculously expensive electronic unit and with oil pressure and water temperature gauges. Picture enclosed.
Regards

[Scorcher IV]

The panel looks very smart, would you be able to share the wiring design as I am sure there a number of people who would rather build your panel than pay for that module. I like the idea of oil and water gauges as well.

[Sen Mora]

Hi,
Attached is the wiring sketch I used to make the panel. A few notes:
The panel is 1/4 in white acrilic
The lights are small colored leds, glow-yellow, oil-blue, water-green, alternator-red
I have purchased couple of pins and inserted them (with wirw tails) into 16pin panel half plug. Engine is prewired for diferent panels, mine was basic it did not have pins for water and oil gauges.
When tested on the boat the engine wire for water gauge did not have continuity so I used extra wire outside of the plug which was in place.
The 3way switch is used for glow plugs (as originally) and to test green light.

Eventually I will make a proper wiring diagram.
Regards