C5 X7 2008 Blower Control Module

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Paul-R
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Re: C5 X7 2008 Blower Control Module

Post by Paul-R »

admiral51 wrote:
22 Dec 2018, 16:42
Do i bridge the wires in the plug or the unit itself ?
The wires in the plug.
admiral51 wrote:
22 Dec 2018, 16:42
Can i put 12 v direct to the unit with it in situ ?
No, that's not the way it works. It might even permanently damage the unit as it works by connecting the motor to earth.
admiral51 wrote:
22 Dec 2018, 16:42
Can i use the plug slot to rotate the unit or will it break ?
Not fully sure what you mean by the plug slot but if you mean what I think you mean, no. You need to get maximum turning force on the unit and you get this by holding the outside edge.
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Paul-R
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Re: C5 X7 2008 Blower Control Module

Post by Paul-R »

If you can get the plug off, great. Bridging the two thick wires on the plug takes the control unit out of the circuit and applies full power to the motor.

You do NOT apply 12v to any of the connections as the unit operates on the earthy side of the blower motor. In fact you can check for a bad earth point by taking one of the thick wires directly to earth. You won't damage anything by connecting an earth to the wrong thick wire as all you would be doing is connecting earth to earth.
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Re: C5 X7 2008 Blower Control Module

Post by admiral51 »

Thanks Paul i have removed my previous post as i had not read your detailed reply above .
I assume engine running blower on and then bridge the 2 thick wires ( Black and Green ) and it should give the blower a kick start, the unit the plug goes into is the one that controls the voltage and is not the blower itself ?
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Re: C5 X7 2008 Blower Control Module

Post by Paul-R »

I put the bridging wire in place and then start the engine up as this stops sparking. Note that the engine has to be running, just turning the "ignition" on won't do it. Run for a few seconds, stop engine and push the plug back on to the control unit. Now, when you start the engine up, the blower should work under control of the buttons.

If it starts with the bridge and then won't with the engine running I'd try bridging again. TBH, this has worked first time for me though.
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Re: C5 X7 2008 Blower Control Module

Post by admiral51 »

Thanks Paul will try that in the morning and yes i was looking at using the plug socket to get leverage to rotate the unit and as you said spray on skin i guessed i may cause damage :)
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Re: C5 X7 2008 Blower Control Module

Post by admiral51 »

Well it works as it should now, bridged the pins and fired her up and blowers on full :)
Switched off, put plug back in and started up again and blower works as it should.
Thanks for all the help
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Re: C5 X7 2008 Blower Control Module

Post by Paul-R »

Good result. It's a ridiculous answer that seems to work.

Until it doesn't again...
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Re: C5 X7 2008 Blower Control Module

Post by GiveMeABreak »

So is this moisture getting into the motor from the air intake then I wonder?
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Re: C5 X7 2008 Blower Control Module

Post by admiral51 »

I do not know about the issues others have had but this happened after the car being sat up for maybe 4 weeks with other issues and yes the car had been open whilst trying to do diagnostics etc and it had been raining over that time and yes the car did get damp.
However thinking back for quite a few months i had heard what i described in my previous post as a chorus of Xantia internal fans on start up and the blower switched on.
Now that i have got the blower working, on startup i did not hear the noise, so can only assume the noise was the blower motor struggling to get going for a period of time.
I think you may be correct in where the moisture is coming from, unlike the Xantia the blower motor is not underneath the air intake so cannot get flooded but also the way it is controlled may lead to the problem?
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Re: C5 X7 2008 Blower Control Module

Post by admiral51 »

Paul-R wrote:
23 Dec 2018, 12:20
It's a ridiculous answer that seems to work.


Yes but who would have thought that on the Xantia the easy way to check cooling fan operation and aircon clutch engagement would be by bridging 2 wires in the dryer plug :rofl2:

For how long it takes to do IF you can get the plug off then once every 3-6 months it is time well spent given that the motor does not get full power under normal startup procedures.
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Re: C5 X7 2008 Blower Control Module

Post by Paul-R »

Indeed. As I have said elsewhere I can do the whole job in five minutes now. Depending on how long this latest "fix" lasts I'm going to look at how feasible it might be to run an extra wire down to the plug to quickly earth the motor without having to dismantle anything.
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C5 Mk3 2010 Blower fan issue

Post by Greg2791 »

Hi,
Just want to share my experince with the above issue. Hopefully it will be helpful for someone.

I had an intermittent issue with the blower fun not working (Citroen C5 MK III mK3 2010). It happened 3 times in 2 years, when was cold then after couple of days the fan started again. Today (4th time the fan is not working) I decided to fix it. The blower resistor (it is not resistor but electronic module - voltage controlled fan speed controller).

Resistor is located around passenger right leg (uk version of C5).

1. Remove the cover at passenger ankle.(one screw)

2 Remove the passenger glove box (plenty of screws) first of all disconnect the box door by removing two white plastic pivots in direction to the middle of the car(box hinges). -small mirror or phone camera may help.

3. Find the resistor which is located in the blower housing quite high - rather closer to the engine behind the air conditioning silver pipes. It has plug with 4 wires. grub the resistor housing, turn left and pull out.

1- GND (-) - green yellow-very tick

2- Signal - white-ish small diameter

3- Motor(-) - black very tick- motor power controlled by the module

4 - +12V red, tick - module power(not motor)

4. Diagnosis:

a) Blower:-resistor connector: short 1(green yellow) and 3(black) through multimeter 20A. start the engine - The blower should run on full speed - current should be around 10A.

b)Module: 9off the car) Connect 0v to pin 1 then +12V to pin 4, then a car bulb 21w between the pins 4 & 3. If bulb lit - module is faulty (possible transistor SUV90N06). Connect multimeter on diodes between 1(-) & 2(+) my has around 3 V open) - the bulb is lighting - module looks OK.

So I did all above, and everything looks good - when I assembled it back - it is working. Still do not know what was the root cause - I think the module cold soldering - so I tried to re-solder as many electronics elements as possible. Assebled again - still works :). I have some photos but I do not know what is the best way to attach them.
Last edited by GiveMeABreak on 05 Jan 2019, 22:12, edited 1 time in total.
Reason: This has been merged with an existing topic
Hell Razor5543
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Re: C5 X7 2008 Blower Control Module

Post by Hell Razor5543 »

You can attach photographs when you use the "Full Editor & Preview" option, below the text entry pane.
admiral51
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Re: C5 X7 2008 Blower Control Module

Post by admiral51 »

Image

I never knew what the wires did all i knew was which 2 wires to bridge so thanks for the info.
The above link shows the plug itself, it is my photo but tech eludes me to post it here direct :oops:
Last edited by xantia_v6 on 06 Jan 2019, 20:03, edited 1 time in total.
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white exec
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Re: C5 X7 2008 Blower Control Module

Post by white exec »

By-passing the module, and so starting the motor at full speed, appears to get the motor turning, and then often operate normally via the module, and at the lower speeds.

That points to the motor bearings having gone stiff/sticky (dried out), to the point where it won't start normally. Reports of cold/damp weather aggravating the situation support this. (The same thing can happen in miniature on fan-assisted cabin temperature sensors, as their bearings dry out with age.)

My guess is that the blower control module is equipped with some current-limiting facility (to protect itself), so a stalled motor will likely cause that to be exceeded, and the motor will probably not start, even when set to maximum speed.

Jumping the module out of circuit (earth jumper link) will allow maximum current through the motor (limited only by the relevant fuse), and so wrench the bearings free. Once freed up, there is likely to be a period of restored working - until the next time.

Sensible cure is to remove the motor, and re-lubricate its bearings, assuming they are accessible. This problem is not unique to PSA; our Toyota (Denso blower) has suffered exactly the same issue. Opening up the motor case was the most difficult bit. Re-oiled (bronze bearings and their felt reservoir pads soaked in light oil) everything worked normally again.