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[Jimbob]

1998
3.0 MV6 Estate
about 105K miles
Virtually no damage as we heard it 'calling for help' and I had put it out and stripped it down before the fire brigade arrived

[redravern]

find expensive adverts for similar cars to fight back with, should be able to get another few hundred with a bit of luck

if you do not agree to the price offered
do you disagree by telephone or letter?

[Ken T]

1998
3.0 MV6 Estate
about 105K miles
Virtually no damage as we heard it 'calling for help' and I had put it out and stripped it down before the fire brigade arrived

Could I ask what was the actual cause of this, was it the power sounder on fire ?.

Sorry, my brain can't see how it can go on fire, NICAD's tend to just get hot, then the vent opens, hydorgen and water come out and that's it. Plus the battery is only about 100mAH when new, so not much capacity, plus its about 10 years old, so will be fairly worn out.
 I got the feeling it might be the powersounder going short, poss the battery leaking and corroding something, and taking the 12V unfused feed from the battery to deck, so this will get very hot, prob melt the wire insulation, which will short all over the place. Hence my earlier suggestion that a fuse in the line should stop this happening again.

This is my theory, I may be totally wrong, but I'd like to get to the bottom of this so no-one elses car goes up.

Ken

[Entwood]

1998
3.0 MV6 Estate
about 105K miles
Virtually no damage as we heard it 'calling for help' and I had put it out and stripped it down before the fire brigade arrived

Could I ask what was the actual cause of this, was it the power sounder on fire ?.

Sorry, my brain can't see how it can go on fire, NICAD's tend to just get hot, then the vent opens, hydorgen and water come out and that's it. Plus the battery is only about 100mAH when new, so not much capacity, plus its about 10 years old, so will be fairly worn out.
 I got the feeling it might be the powersounder going short, poss the battery leaking and corroding something, and taking the 12V unfused feed from the battery to deck, so this will get very hot, prob melt the wire insulation, which will short all over the place. Hence my earlier suggestion that a fuse in the line should stop this happening again.

This is my theory, I may be totally wrong, but I'd like to get to the bottom of this so no-one elses car goes up.

Ken

As I understand the theory ... it's not the nicads that cause the fire itself .. but the car battery !!!

The power sounder is connected directly to the battery .. as it actually senses if the battery is disconnected incorrectly. The nicads are also charged by the car 12v systems, so require a connection for that purpose.

When the nicads leak through old age ?? misuse ?? whatever it is ... they "leak" a corrosive substance onto the PCB inside the powersounder. This can cause a short which then allows the car battery output to run through the powersounder uncontrolled.... as the car battery is capable of supplying mega amps the heat build up can be fast and extrme .. so leading to the fire.

Now my understanding might be wrong .. if so I await correction .. but that is the bare bones of the problem I believe.

The reason some have caught fire "on the shelf" is, I believe that although a nicad is designed to only provide milliamps .. when shorted the whole capacity can be delivered in a very short time .... and that causes much heat. If you don't believe me .. try shorting a CR2032 with a paperclip .. you won't hold it for very long I assure you ... and the nicads in the power sounder are a lot bigger !!

[Ken T]

So if the line were fused it would solve the problem ?. It can't take very much current, Piezo sounders take not a lot, so a half amp fuse at the battery might solve it ?.

Ken

[Vamps]

So, is the answer to simply fit a fuse in the supply from the battery? or am I looking at this too simply?.... :-/ :-/ :-/

[tidla]

So, is the answer to simply fit a fuse in the supply from the battery? or am I looking at this too simply?.... :-/ :-/ :-/

throw it in the bin/battery recyling facility/pond

[Ken T]

That's why we need more information from cars that have just started to go, and then been stopped, exactly what was the problem.

I personally think having an unfused supply is asking for trouble, a potential time bomb, as cables will eventually break down, esp in the car environment, which can go from - 10 to +50 deg C very quickly, which will harden cables and make them crack. An unfused line is asking for trouble, and its only to GM's credit that it appears to last about 10 years before going bad.

A last thought, to those who have disconnected the power sounder, did you insulate the plug ?. I'd hate it to short against some metal, and .........

Ken

[Bent valve]

That's why we need more information from cars that have just started to go, and then been stopped, exactly what was the problem.

I personally think having an unfused supply is asking for trouble, a potential time bomb, as cables will eventually break down, esp in the car environment, which can go from - 10 to +50 deg C very quickly, which will harden cables and make them crack. An unfused line is asking for trouble, and its only to GM's credit that it appears to last about 10 years before going bad.

A last thought, to those who have disconnected the power sounder, did you insulate the plug ?. I'd hate it to short against some metal, and .........

Ken

Taped mine up good and proper

[Ken T]

That's why we need more information from cars that have just started to go, and then been stopped, exactly what was the problem.

I personally think having an unfused supply is asking for trouble, a potential time bomb, as cables will eventually break down, esp in the car environment, which can go from - 10 to +50 deg C very quickly, which will harden cables and make them crack. An unfused line is asking for trouble, and its only to GM's credit that it appears to last about 10 years before going bad.

A last thought, to those who have disconnected the power sounder, did you insulate the plug ?. I'd hate it to short against some metal, and .........

Ken

Taped mine up good and proper

 

Ken

[Kevin Wood]

That's why we need more information from cars that have just started to go, and then been stopped, exactly what was the problem.

I personally think having an unfused supply is asking for trouble, a potential time bomb, as cables will eventually break down, esp in the car environment, which can go from - 10 to +50 deg C very quickly, which will harden cables and make them crack. An unfused line is asking for trouble, and its only to GM's credit that it appears to last about 10 years before going bad.

A last thought, to those who have disconnected the power sounder, did you insulate the plug ?. I'd hate it to short against some metal, and .........

Ken

My thoughts exactly. Wire feeding the sounder is 0.75mm² if memory serves. Might even be 0.5. Lunacy for it not to be protected with a fuse.

I suspect the feed is via one of the large cables to the fusebox area and then on, in weedy cable, to the sounder. This would account for the fact that there is normally also damage in the dashboard area when on combusts.

A power sounder only takes 250mA or so from the 12v supply when sounding.

Kevin

[mantagte]

been speaking to my brother in law and his 2000 (x) Zafira tried the same/similar
last year
located in passenger side wheel arch under  plastic trim
his started smoking at the MOT station
they ripped it out for him
he said no he will not replace it
not just omegas

[Olympia5776]

Vectra B , Astra G and Frontera B too I believe .

[Omega_on_fire]

What about Corsa's?

Ten days ago, a woman popped into the Post Office in the village up the road from me and left her child in car.  The car was an '02 reg Corsa.  Anyway, while she was queuing she looked out and saw that the car had caught fire under the bonnet, so of course rushed out to retrieve her child.

This Powersounder problem makes a big, strong, safe car an absolute death trap, especially if you applied the circumstances of the Corsa woman (leaving your child in the car, or if your wife/girlfriend/boyfriend/husband is asleep in the car while you pop into a shop, nip to a bush...). 

[Chris_H]

So, is the answer to simply fit a fuse in the supply from the battery? or am I looking at this too simply?.... :-/ :-/ :-/

Personally I would put an inline fuse adjacent to the sounder.  That way it's got the protection of being under the scuttle and not easy for someone to remove in advance of theft.

I know stealing an Omega is not the highest of probabilities but Insurance Companies would like to see some attention to detail I'm sure.

PS.  In view of the known issues, this is one occasion when I would agree that the main battery should be disconnected before work is carried out!