Blowers not blowing - C5 tourer '09

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Agour
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Blowers not blowing - C5 tourer '09

Post by Agour »

Hi all!

Got in my car this morning and the blowers weren't working on any settings. It has been cold recently, but the car started up straight away.

I've checked the main 40a resistor for the heaters, and that's ok.

Can anyone give me a clue as to where the heater resistor is located? Or - is there anything else that I should check?

Thanks!

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KennyW
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Re: Blowers not blowing - C5 tourer '09

Post by KennyW »

Have a look at my link

viewtopic.php?t=66786

and this link

viewtopic.php?t=56902

I have a wiring problem to get the bottom off

Kenny

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Re: Blowers not blowing - C5 tourer '09

Post by Agour »

Thanks Kenny, I had a read through of those!

Image

So from what I can tell - the black box with red and white wires going in is the heater resistor?

To get it out it seems like I'll need to remove the glove box, and then the large passenger footwell panel...

Unless I'm missing something and there's an easier way?

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GiveMeABreak
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Re: Blowers not blowing - C5 tourer '09

Post by GiveMeABreak »

That red item is the connection the air heating resistance unit (black rectangular item above in your picture) that's not the heater blower control module.

Have a look at my pollen filter change topic here:

viewtopic.php?t=56902&hilit=pollen+filter

It shows pictures of the blower control unit as I was doing the job.

Agour
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Re: Blowers not blowing - C5 tourer '09

Post by Agour »

Woops! I have the resistance unit out now :)

Image

Any idea what the resistance values across the pins should be?

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GiveMeABreak
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Re: Blowers not blowing - C5 tourer '09

Post by GiveMeABreak »

I have all the info on this here:

viewtopic.php?p=664774#p664774

Agour
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Re: Blowers not blowing - C5 tourer '09

Post by Agour »

Thanks Marc! So from what I understand, I need to put 12v over pins 1 and 2?

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Paul-R
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Re: Blowers not blowing - C5 tourer '09

Post by Paul-R »

No. The control unit is on the earthy side of the motor as the motor is fed with 12v. You need to short the two thick wires on the plug - unfortunately I can't remember the pin numbers but it's obvious.

You put the shorting link (I use a very short length of 1.5mm copper wire from house wiring) on with the ignition off and then start* the engine. At which point the fan will (should!) come on at maximum speed. If it doesn't come on the fault is elsewhere, start by looking for a blown fuse.

My experience is that having been given a kick start on maximum the motor will then work properly with the control unit for quite a while.

*The fan won't come on just by turning the key to the ign position, the engine has to run.

Agour
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Re: Blowers not blowing - C5 tourer '09

Post by Agour »

Thanks Paul!

I didn't try that, in the end I just picked up a new resistor. Well - 2 in fact.

With a replacement in, blowers come on for about 3 seconds after starting engine, then they just switch to a permanent trickle (adjusting settings on dash makes no difference). They worked OK at maximum power for those 3 seconds..

I tried 2 different units from different suppliers and both give the same issue.

Have done a BSI reset, but that didn't fix it unfortunately.

Any ideas?

Rang citroen and they are £133 + VAT... ouch!

Agour
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Re: Blowers not blowing - C5 tourer '09

Post by Agour »

So after reading this thread: viewtopic.php?t=61554&start=15

I tried the bridging method. Got about 17A between green and black.. and what do you know, full power on the vents!

Put a new resistor back on. Same issue as before (only air for a few seconds, then trickle). Euro car parts failing yet again!

Put old resistor on, boom, works perfectly.

How easy is the blower motor to access? If not crazy hard, I might take it out and lubricate the bearings with some WD40

Hell Razor5543
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Re: Blowers not blowing - C5 tourer '09

Post by Hell Razor5543 »

I would NOT use WD40, as this is a water dispersant (hence the WD). 3in1 oil or sewing machine oil would probably be better (other members could advise you better).

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Re: Blowers not blowing - C5 tourer '09

Post by admiral51 »

I cannot expand on the ease or not of access to the motor itself, but having had this issue myself on my old C5 X7 i did the bridge trick and as it went to another forum member i believe it is still working as i have not heard of any issues since.
I am usually wrong on most things techy, think i got something correct once in the whole of last year. lol
But i have been thinking if there is a way the blower itself can be supplied with full power via the various ECU's involved and i cannot confirm as my current C5 X7 is in for Eolys replacement until tomorrow but mainly due to the time of year temperature wise i think there is.
Before you switch the engine off, turn the blower off completely, ie no fan running so the temp screen goes --.
The next time you start the car it should still be showing --, now if you press the demist windscreen button it kicks in the A/C but the system goes into auto mode and i do not think i can get the blower running full chat that quickly by pressing the increase fan speed button.
Like i say only thinking out loud ?
Colin

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Paul-R
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Re: Blowers not blowing - C5 tourer '09

Post by Paul-R »

Agour wrote:
22 Jan 2021, 18:56
Put old resistor on, boom, works perfectly.
If it now works properly then why not persevere with the old control unit?

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KennyW
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Re: Blowers not blowing - C5 tourer '09

Post by KennyW »

I would just leave it.

You are supposed to be able take out the same way the resistor came, :rofl2:

In order to take it easily you have to remove the glove box door and compartment. Once done you get your hand in to remove the plug and rotate the motor to remove.

Replacing is the reverse of removal.

As you seen from my thread I 've not finished checking the wiring but it is too cold here to do that waiting for warmer weather.

Kenny

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Re: Blowers not blowing - C5 tourer '09

Post by Agour »

Paul-R wrote:
22 Jan 2021, 23:05
Agour wrote:
22 Jan 2021, 18:56
Put old resistor on, boom, works perfectly.
If it now works properly then why not persevere with the old control unit?
yeah I'm going to carry on with old control unit now