Zafira fires

The resistors that reduce the fan motor voltage to give different speeds are mounted in the ventilation system airflow to prevent them getting too hot. This is pretty common for a lot of makes.

If the airflow is reduced due to the pollen filter not being changed on schedule, the resistors overheat. There is a non-resettable thermal fuse to prevent a fire occurring.

When that fuse blows, only the fastest fan speed will be available.

Replacement resistor units are available non-OEM, and it's my guess that at least some of them don't have the thermal fuse fitted. If the low airflow situation still exists, or returns, a fire is almost inevitable.

It's likely that Vauxhall's claim is a genuine one.

Chris

Ah right. I've just had a look on ebay and there are tons of non-OE replacements on there. This seller alone has sold 158 of them. It's frightening!

What's frightening about that one? Looks like it's fitted with a thermal fuse to me.

Tim

Where you looking?

Second of the three photos. Component in the the lower centre area beneath the resistors.

Tim

It may not be of the correct temperature rating however.

Chris

It's also marked 250V. Are thermal fuses usually marked with a voltage rating?

It's unlikely you would get one rated lower than 250v - most of the applications will be for domestic electrical equipment running off 250v mains.

They would say that, wouldn't they?

Yes, but that doesn't automatically mean it's not true. Time will tell.

And the question is not about the expiration date of sour cream, the correct question is:

"Why is Sour Cream?"

I doubt you'll ever see accurate statistics.

The main point would be:- Have any of them fitted with genuine parts burst into flames? If so, why would you expect a pattern part to be any better or worse? And why is something so basic as a fan motor speed controller so badly designed in the first place?

It tends to be the first defence of any car maker to blame their poor design on inadequate servicing or the use of pattern parts.

Bit too cryptic for me. ;-)

That's going to be pretty hard to prove, if you look at all that remains after a fire.

In what way do you think it is badly designed?

The basic system of putting the resistor pack in the airflow, with a thermal fuse for protection, has been used on millions of vehicles for perhaps 20 years or more without a problem.

Yes, but in this case it seems the most likely explanation to me.

Zafiras (hateful things, from a manufacturer of hateful vehicles) are exactly the type of car bought by someone who doesn't want to spend a penny more than possible on maintenance. They are viewed as an appliance. Look around a reasonable-size car park, and they are clearly in the main neglected.

All of the reports of fires I have seen have been of older vehicles. if the original design was flawed, it's more likely that the fault would have showed up before now.

Chris

Did he really ask that?

So what's burning after key-off to start the fires? Dust covered pollen filters ? Why's the resistor pack so close to the filter? Or is the Filter sagging onto it??

Tim.

Second of the three photos. Component in the the lower centre area beneath the resistors.

Tim

None of the above.

Most 'victims' have reported a smell of burning whilst the engine is running. That would be the overheated resistors. When the engine (and hence the airflow) stops, the residual heat in the resistor pack sets fire to the plastic ducting it is mounted in.

Chris

Well, yes. But not obviously on the Zafira. It's not something you'd expect to ever replace in many vehicles - and certainly not in a relatively young one.

You as in the Vauxhall spokesman.

Yeh, well, I think it's safe to say that a manufacturer spokesman is going to be even more biased towards OEM parts than anybody with direct personal experience of the sort of cheap chod flogged on fleaBay...