Blower controller cables

[486]

The blower controller is on picture below. I guess the red and black cables are for power of the four levels of fan. I am interested about functions of yellow and green cables. Is there temperature sensor or other "info" coming FROM the blower (controller)? The speed of my blower is increased and decreased sometimes. There were some fixes on the elements of this controller and I am not sure whether it is working good or it is the reason for speed changes. On the other hand, the speed is constant when I change it manually from button (+ / -).

reg.jpg

[Killerko]

Have you opened it up? The issue on mine was just cold soldering spots.. and it was sometimes running on max power then the blower stopped working eventually.. simple re-soldering the spots resolved the issue for me.

[GingerMagic]

That thing is tucked under the dashboard and is in effect a big resistor - these fail over time giving you essentially full speed blower or nothing at all. Have you wiggled the red/black wires to see if the fan bursts into life?

A replacement resistor is only around £30 on eBay or wherever so not a huge outlay.

I've never investigated one. only ever replaced it when it stopped working and left me with a temperamental blower...

[486]

The controller seems working - as I mentioned, I can control all levels of blower with button (- / +). I guess my problems are from bad temperature sensor or bad wire. Not 100% sure but I removed the CD/Radio several times and after such operation the A/C is working normally for some days. I think that by touching wires around CD/Radio I do temporary "repair".

[Killerko]

I found the pictures when mine was acting up.. it's been a few years back, but once resoldered and returned back never had a blower issue again.
I accessed mine via passenger footwell.. it was a bit tricky to remove what I remember, but doable.
Btw: mine was working as well.. but it was temperamental... sometimes just decided to go full blast, sometimes just not at all.. most of the time was working ok, until it stopped working completely.

[GingerMagic]

Oh, I see.

Are you concerned about the speed of the fan changing on its own?

This is normal - its the temperature sensor inside the grill by the interior light telling the blower to increase or decrease the temperature inside the car to correspond with what you've set on the climate control panel ( as far as I'm aware)

[486]

It seems the problem is in interior temperature sensor (near the lamp) or cables/connectors. Today it showed +63°C for 1-2 seconds and then the normal value +23. It was read with OBD (not Lexia) but I hope it is the same at least for this sensor. BTW, is there recommended type or model for OBD II dongle? I want to buy one and be able to read such values.

[Doggy]

Best bet is to search 'Lexia 3' on eBay, should come with PP2000 and/or diagbox software, (ideally both).
Typical price nowadays £60 or a little less