Heater Blower can't be switched off

MikeT · Post by **MikeT** » 30 Jun 2007, 18:55

Here's a good one!... I put the demisters on full blow and now it won't turn off. I can redirect and change the temperature etc. but I can't turn the blower fan off - it's stuck on full power. Until today, it's always worked fine.

I have climate control with A/C and had previously noticed the fan blower only operated after a short delay from engine start.

Now, the blower comes on as soon as the ignition is turned on.

Does this ring a bell with any of you experienced owners? I'll have to decipher the Haynes BOL again now.

den169 · Post by **den169** » 30 Jun 2007, 19:16

It would ring a bell if it was a c5 my blower was on full blast in the c5 with climate control,The fault was a printed circuit chip etc built into a alloy block with fins which goes in the bottom of the heater just to the left of the footbrake.Could be that.but mines a 2003 c5.

AndersDK · Post by **AndersDK** » 30 Jun 2007, 19:21

Peter N or Clogzz will be around soon 8)

MikeT · Post by **MikeT** » 30 Jun 2007, 20:46

Haynes diagram shows a speed control and speed resistance module in the circuit. Could be either one of those I guess.

I also searched the forum and it seems a certain transistor failing is a common fault.

One poster had rainwater leaking over the blower from a cracked windscreen scuttle...

My scuttle is also broken and rainwater is dripping in to the passenger footwell

Post by **Peter.N.** » 30 Jun 2007, 21:08

Yep, chances are that the regulator transistors on the motor are faulty, although I think mine would turn off, just ran flat out when switched on, but as it has a permantly live feed (when the engine is running) I would say, short circuit transistors.

MikeT · Post by **MikeT** » 30 Jun 2007, 21:50

Well this one won't turn off, even with the engine not running - does that change anything?

Post by **CitroJim** » 01 Jul 2007, 08:05

MikeT wrote:Well this one won't turn off, even with the engine not running - does that change anything?

Tha was the exact symptom I had when one of my blower transistors went. Fan on full as soon as the ignition was turned on. There should be a delay before the fans start on initial ignition on and they should not run until the engine is started and running.

Must be something specific to a MKII model.

The transistors are available from Farnell Electronics and not hard to swap if you are handy with a soldering iron.

Post by **Peter.N.** » 01 Jul 2007, 08:25

The 'when the engine is running' may have been a red herring on my part, as I think its the supply to the control unit that's only there when the engine is running - apologies. It depends how the transistors have failed - collector/base or collector/ emmiter short. Transistor type on my signature.

MikeT · Post by **MikeT** » 01 Jul 2007, 09:18

citrojim wrote:
Tha was the exact symptom I had....

Must be something specific to a MKII model.

The transistors are available from Farnell Electronics and not hard to swap if you are handy with a soldering iron.

And MKI's jim

We got a maplins in Bournemouth and I can solder in my sleep but I better cure the water leak first.

Anyone got a spare scuttle they don't want or would silicon sealant underneath work? Worth a try I think. Thank you!

MikeT · Post by **MikeT** » 01 Jul 2007, 09:24

Peter.N. wrote:The 'when the engine is running' may have been a red herring on my part, as I think its the supply to the control unit that's only there when the engine is running - apologies. It depends how the transistors have failed - collector/base or collector/ emmiter short. Transistor type on my signature.

Mistakes happen Peter, I'm grateful for all you kind people here and the assistance you volunteer, thank you

Post by **CitroJim** » 01 Jul 2007, 09:28

Mike,

Maplins won't have them. Farnell are the only source I know of.and they have a £20 min order. I have a spare set so if you want 'em let me know.

This (my experiences of swapping them) may be of interest. Do another search on "transistor" and loads of very useful stuff will come up.

http://www.frenchcarforum.co.uk/forum/v ... transistor

Silicone sealant (a good autmotive quality one) will be fine Mike. Do check under your carpets for water though and be prepared to have the carpets out

MikeT · Post by **MikeT** » 01 Jul 2007, 09:46

If I opt to repair, I will buy from you - how many do I need? Problem is, I'm finding too many faults with this car and as much as I like it (air-con, cheap veg fuel etc), I think I'll have to sell it on.

My carpet is wet so they will come up if I tackle the blower. I have an alarm fault too and believe the module may also be immersed

Cheers

Post by **CitroJim** » 01 Jul 2007, 09:54

Mike,

I was just thinking that you are going through all the same pain as I had on my Activa. I know exactly what you are going through and I got to the point when I got so despondent I thought of scrapping the damm thing.

This after a long period of totally trouble-free (which continues) with my old TD Xantia.

Stick with it, you have come so far already! Get these problems sorted and I guarantee a long period of trouble-free running. My Activa (touch wood) is now OK and I'm down to doing minor work now. Yours will be the same very soon.

It'll be worth it in the end, you'll end up loving it and feeling sorry for all the non-Xantia drivers out there and the expertise you have gathered will make you very confident with it.

PM me your address and a pair of transistors will be in the post tomorrow afternoon.

MikeT · Post by **MikeT** » 01 Jul 2007, 10:10

Thanks for all the support and encouragement Jim but if I was to show you all I've found so far, you may well agree it should be scrapped. I won't go into detail here, but take it from me it's too much, better to spend the money on a nicer example of Xantia I think. I can use my new found experiences/expertise to better judge my next purchase

I only bought the car because it was cheaper than re-taxing my Granada! I've owned a Xantia before... and with this one being TD, taxed and mot'd, thought it would be a good experience so bought it!

The Xantia does have some major advantages over my Granny and intially I was inclined to keep it and sell the Ford but this Xantia is proving to need just too many jobs and too much money for my failing body and meagre wallet.

By the way, do you know of any easy way to temporarily disable the blower other than removing the fuse?

Thanks, Mike

wheeler · Post by **wheeler** » 01 Jul 2007, 12:53

MikeT wrote: I have an alarm fault too and believe the module may also be immersed

Cheers

Your probably right on that one, also check the 30 pin brown connector in the footwell too, check that the pins in it aint corroded.