Heater blower runs flat out constantly

[smoker]

Hi,
Car is a 52 plate Xsara (not Picasso) 110 hdi estate with climate control.

As title, turned fan on a bit yesterday as car misting up and it came on flat out irrespective of speed controller position. It does this now whenever the engine runs. Heating and A/C still seem to work well. Various searches suggest that this is a common fault being either a cigarette-pack sized controller in the driver's footwell, or the transistor pack on the motor itself.

I can't readily see anything that looks like the cigarette-pack sized device anywhere around the drivers footwell, despite lying on my back with a torch (although I haven't stripped anything out in order to search for it). If there is one is it buried or should I be able to see it?

If it's not this, I guess my best solution might be a whole new blower unit - ECP around £60 or £80 depending on make? I've seen the guide on replacing transistors but not sure I have the time or capability to make a good job of it.

Any guidance appreciated, thanks.

[JohnD]

When my daughter had a Xsara it started doing that. I replaced the resistor pack on it and put it all back together again. It worked fine - for about two weeks before stopping altogether. I replaced the complete motor from ECPs. Best to remove the glove box for access.

[RichardW]

If it's got climate it will have the transistors on the blower unit. You can buy a replacement control unit on e-bay for about £20, and it's easy to change. I managed it on my sister's Xsara without removing the glovebox....

[white exec]

If like XM, some of these cheap Chinese blower control units on ebay are poor quality, and very short life. Apparently, it's the semiconductors that perish.

[CitroJim]

It may be similar to the Xantia one... Easily fixable if so...

https://www.frenchcarforum.co.uk/forum/ ... 12&t=22398

[smoker]

Thanks for the responses.

I'm now convinced that the problem lies with the fan motor and the bits fitted to it. There doesn't appear to be any other control box that I can find.

I've looked at the replacement transistor/resistor fixes available on "that auction site" but am wary about fitting poor quality parts that may not last well. My decision is now whether to try and replace the individual components i.e transistors, or buy a whole new unit. At any other time of year I'd probably be able to live without the fan while I fiddled, but cold weather = condensation etc so may have to stump up for whole new unit. Grrrr, more expense...

Cheers

[myglaren]

If you are concerned about the cost then try Farnell
The parts will be more expensive but more likely to be of good quality.
Note that small orders are charged with a (£3.60 IIRC) handling/postage cost.

Or RS who are similar but may have a trade counter near you - they sell to non-trade people too.

Having said that I have bought tons of electronic bits and bobs on eBay and Amazon and haven't suffered any failures that weren't my own stupid fault.

[CitroJim]

A well-known auction site is alleged to be awash with counterfeit electronic components... Been quite a lot of discussion about it over on the wireless forums recently...

Best always to buy from the likes of CPC Farnell. It might be a little dearer but quality is guaranteed and for automotive electronic repairs you really do want to use the best...

It's easy to beat their handling charge... Try to buy the items from CPC rather than Farnell.. They're just different faces of the same firm...

[white exec]

There's also Rapid Electronics (part of the Conrad group), in Colchester.
You can register and immediately order on-line. UK despatch is free, iirc.
Excellent source of top-quality components.

[CitroJim]

There's also Rapid Electronics (part of the Conrad group), in Colchester.
You can register and immediately order on-line. UK despatch is free, iirc.
Excellent source of top-quality components.

Yes, absolutely Chris... They are good at some quite obscure stuff too...