C3 Interior Fan Problem.

quattrojames · Unread post by **quattrojames** » 11 Mar 2010, 20:06

Hi

I've registered today to try and pick your brains on a problem with my wife's car. She has a 2003 C3 1.4 HDi Exclusive - this has the digital climate control system.

The problem is with the ventilation fan. Now firstly the climate control panel doesn't become live unless the engine is on, ie you can't run the interior fan unless the engine is running (thus drowning out the fan noise when testing...) - is this normal?

Due to this I can't really hear the fan in operation.... Even at standstill there is some air movement from the vents, so I'm guessing the fan is working. But it doesn't increase in speed when you manually override the AUTO system.

Anyone got any ideas? The fuse is ok, and given the fact the fan seems to be blowing I'm guessing it's not the motor or brushes.

Any help gratefully received.

James

Clogzz · Unread post by **Clogzz** » 12 Mar 2010, 11:43

Hi James, and welcome to our troubles.

Doesn’t look like there are any ideas about the C3, and neither do I have any, but going by other models, it’s normal to have no fan spinning until after the engine is running.
There’s a sequence controlled by the engine and climate control ECU’s, with the interior fan starting a few seconds after the engine, and the compressor starting last.

Since you have air flowing, the fan motor should be good, but the pollen filter may still be the original one from 2003, and must be a good black by now.
Larger cars have the filter under the dash, but smallish ones may have it under the bonnet.
I’ll go trawling for pictures or diagrams, and will be back if I find anything of use.

----------------------------------------

Back.

The filter is item 11, but not clear as to where it is.
Enjoy some contortions.

old'uns · Unread post by **old'uns** » 12 Mar 2010, 18:00

i know nothing of the C3 system but on a C5 a common fault is the resistor board on D/S of heater which shows up as the fan speeds not being able to be increased from 1, although i think the fan will start at first then shutdown.

BigBarney · Unread post by **BigBarney** » 12 Mar 2010, 19:43

Hi James,

I have an 05 registered C3 with the same climate control.
If you switch on the windscreen boost (top left switch) and select internal circulation (second switch down on left) and then increase the fan speed to maximum using the + switch on the bottom row, the fan should blow hard enough to blow your wig off!
If it does not and you say the fuse is OK, then I am at a loss to help you at the moment but I will see if I can find an answer for you.

quattrojames · Unread post by **quattrojames** » 13 Mar 2010, 09:40

Clogzz wrote:Back.
The filter is item 11, but not clear as to where it is.
Enjoy some contortions.

Thankyou very much for your help, I hadn't thought of the pollen filter. I know where as it is as I have replaced it, it was probably three or more years ago though

- I will check it today and report back

old'uns wrote:i know nothing of the C3 system but on a C5 a common fault is the resistor board on D/S of heater which shows up as the fan speeds not being able to be increased from 1, although i think the fan will start at first then shutdown.

Thankyou - this doesn't sound so simple!

Silly question, but what's D/S mean?
It used to be (and still is a bit) an intermittent problem, but does it mostly all the time now.

BigBarney wrote:Hi James,

I have an 05 registered C3 with the same climate control.
If you switch on the windscreen boost (top left switch) and select internal circulation (second switch down on left) and then increase the fan speed to maximum using the + switch on the bottom row, the fan should blow hard enough to blow your wig off!
If it does not and you say the fuse is OK, then I am at a loss to help you at the moment but I will see if I can find an answer for you.

Hi Barney - I will try the boost test and hold onto my wig

I'll update here later with my findings and see if it gives anyone any more ideas!

Thanks for your help, James

quattrojames · Unread post by **quattrojames** » 13 Mar 2010, 21:21

Right well I did a few checks today.

The pollen filter was dirty, but not the problem. I removed it and it made no difference. So I manhandled myself into the passenger footwell so I could hear the fan running and fiddled about with connections, linkages etc.

Bizarrely when I wiggled the linkage in the below pic - which is the lever that moves when you vary the temperature - strangely when I moved this by hand the fan sprang into life!

Since then (for one short journey at least....) the fan was reported as working correctly. So I'll just have to wait and see what happens.

quattrojames · Unread post by **quattrojames** » 23 Mar 2010, 22:10

Sadly I'm back

Whatever I did was a very temporary fix. I've done some reading around on here, and from THIS it sounds like it could well be the heater blower resistor pack (module) - does this sound like a likely solution to the problems I've listed? Can anyone advise?

The price seems to vary between £35 and £135 from reading the posts, depending on the type of aircon system fitted. This one has a fully automatic digital climate control, does anyone know the likely price of a replacement should it be this at fault?

Thanks in advance

Unread post by **myglaren** » 23 Mar 2010, 22:19

Mine was £35 + VAT. IIRC

quattrojames · Unread post by **quattrojames** » 23 Mar 2010, 22:20

myglaren wrote:Mine was £35 + VAT. IIRC

For a C3 with digital climate yeh?

Unread post by **myglaren** » 23 Mar 2010, 22:30

C5 with digital climate.

quattrojames · Unread post by **quattrojames** » 23 Mar 2010, 22:37

From your experience is it most likely the same module?

Unread post by **myglaren** » 23 Mar 2010, 22:50

I'd say that it most likely is.

quattrojames · Unread post by **quattrojames** » 24 Mar 2010, 21:08

Great thankyou.

I now need to persuade the wife to spend £40 on her car .....

Unread post by **myglaren** » 24 Mar 2010, 21:35

You may be able to remedy the problem for less than that

Locate and remove the unit, open it up and look at the output transistors and their connections. They can get very hot and either burn out or desolder the connections.

You should be able to replace the output transistors for around £5.

The unit is generally located above and to the left of the clutch pedal, behind the trim, and retained with two 6mm hex screws.

Images are not from my car but an automatic, location is the same though.

quattrojames · Unread post by **quattrojames** » 24 Mar 2010, 22:15

Hmmmmpph - many thanks for the idea, but I fear it may be well outside of my knowledge base! Unless someone has a 'How to' guide....?