Heater blower failure

I have had a poke around of the 2 plugs on the heater blower controller with a multimeter.
A is an earth and B is a 14.4v supply which is live when the engine is running - I think this is power to the fan controller.


1 and 2 are not used,
3 is a 14.4v supply and 4 is its earth
5 and 6 carry a variable voltage depending on the fan speed selected.
I am not sure if this is going to help much...

Bill,

I think we have got to the stage that either it goes to a Service agent ( good luck if they are as bad in the UK as they are in Aus) or get the module through eBay ( we got ours from Sensors4Us) and replace it. Worst case scenario here is that it might cost 35 GBP to eliminate it as a problem but from what I have been reading both here and in Aus it generally solves the problem and posts do indicate a big problem with the actual motor.

I have just been reading a series of posts here in Aus from back in 2006 and before eBay. Some locals had identified the Mosfet involved, purchased one for between $2 and $4 and then replaced it in the module (plus a small cost for silicon heatsink grease) and this fixed the problem. Looks like its the mosfet that is a bit delicate?

Having built many stereo amps back in the 60s I am not all that confident or energetic enough to try this so a part swap is always my method of choice. Besides the old part, if I leave it on my desk at work is always a good conversation starter with the young blokes I work with. Life in the old dog yet.

David

Just joined the forum and searched through old posts and found this. I too have a blower that only works on max setting so I assume I have the same problem. I have located the unit as in the pictures. It looks like one single screw to remove the unit, is this correct?

Yes, one screw on the one I have removed before.

I have a 2002 C3 Exclusive with Auto AirCon with a problem like the one you have been discussing, and although the display tells me that the fan is blowing, it would appear that I have exactly the same problem with just a small amount of ram effect air coming through the system, and no fan assistance.

I will have a look at the module as you have discussed when there is a bit of daylight tomorrow.

Hopefully this will answer my problem.an denable a solution

Pensfold

SOLUTION for fans / blower not working, C3 2005, digital control, A/C

This was the solution I put together after my fans stopped blowing, but the temperature control worked, - would not have been possible without the tips and advice from this thread & also this Citroen C3 heater fan not working topic

Replacement of the rectifier on the Heatsink:

You need: a torx screwdriver/ bit, soldering iron, desolder pump, solder and one of these:
IRFZ48NPBF N-Channel MOSFET.

https://uk.rs-online.com/web/p/mosfet-tr ... s/5409957/ - or equivalent.

It is a reasonably easy job, read above & the other thread here: Interior heater fan not working - for location of the heatsink.

Once you have got the single torx screw out & undo the harness connections to the heatsink, the next step is to lay the heatsink flat, soldered side down.

You'll see the metal retaining clip either side of the rectifier, you need to unclip each side.

Next, turn the heatsink upside down, desolder the three squares holding the rectifier in place, you will now be able to remove the rectifier & replace ...solder the new one in place, reclip it in & once you connect the heatsink back to its harness & screw the torx back to hold it in place, thats it... your done

Images:

pinewomble wrote:SOLUTION for fans / blower not working, C3 2005, digital control, A/C

This was the solution I put together after my fans stopped blowing, but the temperature control worked, - would not have been possible without the tips and advice from this thread & also this Citroen C3 heater fan not working topic

Replacement of the rectifier on the Heatsink:

You need: a torx screwdriver/ bit, soldering iron, desolder pump, solder and one of these:
IRFZ48NPBF N-Channel MOSFET.

https://uk.rs-online.com/web/p/mosfet-tr ... s/5409957/ - or equivalent.

It is a reasonably easy job, read above & the other thread here: Interior heater fan not working - for location of the heatsink.

Once you have got the single torx screw out & undo the harness connections to the heatsink, the next step is to lay the heatsink flat, soldered side down.

You'll see the metal retaining clip either side of the rectifier, you need to unclip each side.

Next, turn the heatsink upside down, desolder the three squares holding the rectifier in place, you will now be able to remove the rectifier & replace ...solder the new one in place, reclip it in & once you connect the heatsink back to its harness & screw the torx back to hold it in place, thats it... your done

Images:

F5409957-01.jpg

Thanks for the information.

C3driver52 wrote: ↑Thu Jun 06, 2013 1:11 pm I have had a poke around of the 2 plugs on the heater blower controller with a multimeter.

Citroen_C3_Fan_Controller_connections_climate_control.jpg

A is an earth and B is a 14.4v supply which is live when the engine is running - I think this is power to the fan controller.


1 and 2 are not used,
3 is a 14.4v supply and 4 is its earth
5 and 6 carry a variable voltage depending on the fan speed selected.

blower-fan-motor-control-voltages-citroen-C3-2002-climate-control.jpg

I am not sure if this is going to help much...

Hello, can you please tell me how do you connect your multimeter to take these readings? I mean you get one of the sticks to pin 5 the other where do you stick it to take a reading of 6.0v? As you can tell I am nube to all electronic staff.

Thanks a lot

Nikos wrote: ↑Sat Jun 09, 2018 12:35 pm Hello, can you please tell me how do you connect your multimeter to take these readings? I mean you get one of the sticks to pin 5 the other where do you stick it to take a reading of 6.0v? As you can tell I am nube to all electronic staff.

Thanks a lot

Hi.

If you are not good at electronics, you will find it easier to just replace the blower controller unit. They are not expensive and are often the cause of fan blower failure. Remove yours and compare it with the ones from this list to find a match.

If you need further help in diagnosing after changing the controller, post a question here with all the relevant and previous work you have had on the blower fault.

We have the facelift model with the same problem, trouble is their is a panel in the way and cannot work our how to remove it!