Volvo Penta Alarm Module - Simpler fix

superheat6k

superheat6k

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Having followed and contributed to the recent thread on the home made VP alarm module ...

http://www.ybw.com/forums/showthread.php?406305-Home-Made-Volvo-Penta-2003-Instrument-Panel

I have sussed a simpler possible fix. Certainly remaking the electronics is not a simple task, and the end result is less tidy.

So assuming the common problem is that individual alarms do not make the buzzer sound, but the test button still works to make the buzzer sound, then the likelihood is that the internal Zener has blown.

However, by connecting a couple of diodes in the connecting wires on the multi way plug the alarm function can be restored, and this is hugely simpler than making the module anew.

The pins can be removed by carefully prying at the side of the pin to release the lock catches.

Simply connect diodes +VE line towards the Blue / White (oil pressure) and Brown / White (temperature), with both neg wires to the Black connection. This should restore the alarm buzzer function by grounding (to -VE) out the test circuit if an individual alarm illuminates.
 
Well the first one has taken me all week, and a lot of de=soldering and swearing. I have four of these on my boat and whereas the home made one has some extra bells and whistles, not sure my marriage will survive another three re-makes !
 
I replaced the alarm module with a new one and the buzzer still fails to work. I replaced the buzzer and it still doesn't work even on the test button. Any ideas?
 
superheat6k said:
Having followed and contributed to the recent thread on the home made VP alarm module ...

http://www.ybw.com/forums/showthread.php?406305-Home-Made-Volvo-Penta-2003-Instrument-Panel

I have sussed a simpler possible fix. Certainly remaking the electronics is not a simple task, and the end result is less tidy.

So assuming the common problem is that individual alarms do not make the buzzer sound, but the test button still works to make the buzzer sound, then the likelihood is that the internal Zener has blown.

However, by connecting a couple of diodes in the connecting wires on the multi way plug the alarm function can be restored, and this is hugely simpler than making the module anew.

The pins can be removed by carefully prying at the side of the pin to release the lock catches.

Simply connect diodes +VE line towards the Blue / White (oil pressure) and Brown / White (temperature), with both neg wires to the Black connection. This should restore the alarm buzzer function by grounding (to -VE) out the test circuit if an individual alarm illuminates.
Click to expand...

Having difficulty visualising this,......are you connecting the new diode anodes to pin 7 with the individual cathodes connected to pins 3 and 4 In effect turning on the transistor which then bypasses the zener and the series diode to give the buzzer a positive in the event of low oil pressure or water over heat. If I've understood this correctly top marks for lateral thinking!

Michael
 
Last edited:
mjf107 said:
Having difficulty visualising this,......are you connecting the new diode anodes to pin 7 with the individual cathodes connected to pins 3 and 4 In effect turning on the transistor which then bypasses the zener and the series diode to give the buzzer a positive in the event of low oil pressure or water over heat. If I've understood this correctly top marks for lateral thinking!

Michael
Click to expand...

Yes - but this fix only dawned on me when I was testing the home made module, and wasn't looking forward that much to tackling the remaining three.

The conundrum I now have is three modules with conventional operation, plus one home made with revised function, whereby the alarm test button makes the lamps all alight as well as the buzzer sound.

This home made one also has an irritance not yet worked out - when I switch on, the Alt lamp, which is now switched by a relay instead using a resistor to power the Alt field, remains off, but if I press the test button it lights and then stays on after release.

I suspect the resistance through the field winding is causing the relay to partially energise - my concern is the alarm just might not work if the Alt stops generating.
 
superheat6k said:
Yes - but this fix only dawned on me when I was testing the home made module, and wasn't looking forward that much to tackling the remaining three.

The conundrum I now have is three modules with conventional operation, plus one home made with revised function, whereby the alarm test button makes the lamps all alight as well as the buzzer sound.

This home made one also has an irritance not yet worked out - when I switch on, the Alt lamp, which is now switched by a relay instead using a resistor to power the Alt field, remains off, but if I press the test button it lights and then stays on after release.

I suspect the resistance through the field winding is causing the relay to partially energise - my concern is the alarm just might not work if the Alt stops generating.
Click to expand...

Thanks for the reply, not followed the other threads to any great depth. Do you have a sketch of the relay set up, what's the advantage of doing it that way?

Expanding your idea of using extra diodes you could.........By using1 additional diode you could have alarm sound when the Alt is not charging. With 2 further diodes you could have the water temperature light come on with the test switch
Michael
 
mjf107 said:
Thanks for the reply, not followed the other threads to any great depth. Do you have a sketch of the relay set up, what's the advantage of doing it that way?

Expanding your idea of using extra diodes you could.........By using1 additional diode you could have alarm sound when the Alt is not charging. With 2 further diodes you could have the water temperature light come on with the test switch
Michael
Click to expand...
Having made one with the relay which separates the Alternator field from the indicator lamp, I found it doesn't quite work as intended. I then applied the simple cable mounted diode fix to the remaining three modules, two of which worked, but one didn't. So remaking this one I decided to go for a compromise where the Alt lamp is as original, but I removed the diode to this from the water temp and added diodes to the alarm test switch -VE conn, so now the other lamps do come on with the alarm test.

The problem with the alt field is its swing from low resistance to -VE to +14volts, hence my idea to use a relay. Also at -VE it doesn't conduct that well due to the field resistance.

One of the problems with this idea of making a new PCB is the overcrowding of the veroboard, and in my view the lack of clearance between neighbouring tracks. I used 9 vero tracks, and would suggest using every other track to avoid crowded tracks not spilling solder onto the neighbouring tracks. Vero is essentially for amateur solderers and is not that user friendly IMHO.

I need to download the second mod drawing to Dropbox so I can place a link on here.
 
I have just fixed a module for another forumite where I recovered the original box and all four lamp mounts, I affixed these to the replacement circuit board which slid into the original locating slot. The finished result is close to the original.

I did this to the original circuit spec, as the soldering becomes difficult with more components sharing the tracks.

If any one is stuck for their Volvo Penta alarm module not working properly PM me either for me to fix it or to supply the instructions, for which a small donation to the RNLI wil be suggested. Seems very common for the internal diodes to pack up - the fix costs about £20 for the bits.
 
superheat6k said:
Having followed and contributed to the recent thread on the home made VP alarm module ...

http://www.ybw.com/forums/showthread.php?406305-Home-Made-Volvo-Penta-2003-Instrument-Panel

I have sussed a simpler possible fix. Certainly remaking the electronics is not a simple task, and the end result is less tidy.

So assuming the common problem is that individual alarms do not make the buzzer sound, but the test button still works to make the buzzer sound, then the likelihood is that the internal Zener has blown.

However, by connecting a couple of diodes in the connecting wires on the multi way plug the alarm function can be restored, and this is hugely simpler than making the module anew.

The pins can be removed by carefully prying at the side of the pin to release the lock catches.

Simply connect diodes +VE line towards the Blue / White (oil pressure) and Brown / White (temperature), with both neg wires to the Black connection. This should restore the alarm buzzer function by grounding (to -VE) out the test circuit if an individual alarm illuminates.
Click to expand...

Hi just started following your ideas on module repair. I am really interested in what you suggesting. My unit has just failed and I would like to have a go at what you recommend as a fix. Trouble is Im bit lost.
Don't suppose you have any pictures or are able to walk a techno/phobe through the repair process?
 
Seasone said:
Hi just started following your ideas on module repair. I am really interested in what you suggesting. My unit has just failed and I would like to have a go at what you recommend as a fix. Trouble is Im bit lost.
Don't suppose you have any pictures or are able to walk a techno/phobe through the repair process?
Click to expand...
Top left of Original Post gives the date of posting.
Seeing as it was 7 years ago Mr Superheat may not be able to reply directly?
You can check to see if he is still around, somehow.
 
superheat6k said:
I have just fixed a module for another forumite where I recovered the original box and all four lamp mounts, I affixed these to the replacement circuit board which slid into the original locating slot. The finished result is close to the original.

I did this to the original circuit spec, as the soldering becomes difficult with more components sharing the tracks.

If any one is stuck for their Volvo Penta alarm module not working properly PM me either for me to fix it or to supply the instructions, for which a small donation to the RNLI wil be suggested. Seems very common for the internal diodes to pack up - the fix costs about £20 for the bits.
Click to expand...
Hi, Any chance of being supplied with instructions on how to fix my alarm module?
 
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