C4 Heater/AC not working

[Lia3110]

Hi everyone,

I seen in an old tread that people were having similar issues but wanted to get some advice specific to my problem.

Ok so, I have a 2005 Citroen C4 and the other morning I started the car and the heater/AC just didn't come on. But it was working fine the night before. The rear window demist still works. The lights come on and everything on the screen works fine.

I have changed fuse 11 under the bonnet and still nothing. When you put it on you can hear a buzzing noise as if it's trying to start and clicking noises when I press the buttons and fluid is fine as well.

Any help would be much appreciated. And if you need any more info just let me know.

Thanks
Leanne

[GiveMeABreak]

Hi and welcome Leanne.

It's a common problem and seems to be moisture getting into the bearings. These units have a 'slow start' feature that gradually ramp up the power, but it can also be insufficient power to free the bearings when starting off at the slower speed.

Others have temporarily bypassed the blower control module so that it gets full power to give it some welly to start it off.

You'll find this will likely happen intermittently.

Paul has posted up a some info - when I find it I'll link to it here.

Here you go:

viewtopic.php?f=3&t=61293&hilit=bearing ... 30#p592581

[Lia3110]

great thanks, i shall go and have a read and see what i can do.

I'm not sure if i was clear enough before, when i said you can hear a buzzing noise its very faint and goes off within seconds, it is the same kind of noise as you would get if you were inserting a CD into the CD player and it happens when i press the AC button or if i turn up to power of the fan from min to max. It stays the same even if the car has ran for some time.

Anyway thanks again hopefully get something sorted, i really appreciate the help.
Thanks

[GiveMeABreak]

Those noises could be just the air distribution or mixing flaps moving about to adjust the air flow or air mixing to get to the set temperature.

[Lia3110]

Thank, I have been on the link and had a wee look and I can see that bridging 2 wires has been suggested but I'm not quite following how I would do this and which wires it would be.
Would you be able to go into a bit more detail?

[admiral51]

Hi Lia3110

Assuming yours is the same as mine then if you can remove the plug then bridging the wires is easy.
download/file.php?id=11903&mode=view
That is a picture of the plug showing the 4 wires.
With the plug unplugged put a wire across the Black and Green/Yellow wire pins, start the car and the try the blower, fingers crossed it works.
Switch off, remove bridging wire and plug back in.
Stat car, try blower, if all okay put trim back in place

[GiveMeABreak]

You'll need to remove the front passenger well side trim with a trim tool.

The Blower control module on your car is here:

... and it looks like this:

There is a connector on the end and the module is removed with an anti -clockwise turn

[Lia3110]

OK thank you both for the help, i shall try this today if i get a chance and i will get back to you as soon as i have any results.
Really appreciate the help

Leanne

[admiral51]

The module itself is awkward to remove and will involve scraped skin and swear words so if you can unplug the plug so much the better

[Paul-R]

The module itself is awkward to remove and will involve scraped skin and swear words so if you can unplug the plug so much the better

Chicken and egg. I found the plug a real swine to take off and found it easier (relatively speaking) to unscrew the control unit and then take the plug out.

Make of that what you will!

[admiral51]

I still have all my skin on my hands and to be fair it is now no longer in my custody

[Paul-R]

Once you have the hang of it knuckle skin remains unbroken each time you take it out (oo-err missus).

[Lia3110]

Hi everyone i finally got around to getting it sorted, it turns out it was the under bonnet fuse box that was the issue and i had to replace it.
Thanks so much for all your help and suggestions

Leanne

[Paul-R]

Wow. How did you trace the problem to the fuse box?

[snawheed]

Iv got same problem, no heater blower, checked fuses changed motor, changed resistor, changed control panel, looks like il have to go down the "bridging" option.
C4 2.0 hdi vds