Blower advice on facelift C5 2006 auto climate control

[sjc204]

Citroen C5 Exclusive 2.0 HDI Estate 2006 with the automatic air con / climate control (which has been excellent) (VIN VF7**************[VIN obfuscated, can be read by forum staff])
Hi all,
Last time the blower worked was to defrost on an icy morning a few weeks ago, so it was running hard for a little while. Since then it has not operated. You would think a fuse blew, but apparently not.
When I operate the fan controls, the icons in the digital display seem to work correctly. I can find no blown fuses in the engine fusebox or the cabin fusebox. (The fuse numbers are nothing like in the Haynes manual.) The lights on the air con control panel are working as normal.
I've accessed the blower motor and it looks fine. The connector has heavy red and black cables, and two thin coloured wires, green/yellow and violet (again unlike the diagram in Haynes). Battery voltage appears between red and black terminals on the cable when the ignition is on, and higher when the engine is running.
The blower motor has a circuit board attached, see pic. This appears fine. It appears to have an IC, a load of triacs and a temp sensor (?). Nothing has melted or burned, there is no smell. Under the pcb I can see the motor windings, again everything looks fine and no smell.
I cannot find a resistor pack on the heater unit. I have looked both sides. I guess that the circuit board controls the motor according to digital signals from the control panel, as this model doesn't have a mechanical fan switch.
I have tried applying power to the red and black terminals, but nothing happens. Not surprising if it is wanting a control signal, but I am not sure what that might need.
I've withdrawn the control panel, and all the multi plugs look fine. Not sure if there is any way to test it so I can go no further.
Can any wise person please suggest my next move to get the blower working?
I really want to keep this car going as it is such a good drive.
Many thanks

[mickthemaverick]

The first thing to try is a BSI reset in case the ECU has got into a loop. Follow the procedure in the link below and then you will know your fault finding starts from a 'clean sheet'

viewtopic.php?p=601679#p601679

[PaulC5]

When the blower stopped working on our Cactus it was the blower resistor pack that had failed. On the C5 it can look like this so gives you an idea what to look for https://www.autodoc.co.uk/car-parts/blo ... i-break-re

[sjc204]

The first thing to try is a BSI reset

Thanks, presumably I have to connect everything back before doing that. Wish I had thought of that before I started taking the footwells apart!

[sjc204]

When the blower stopped working on our Cactus it was the blower resistor pack that had failed. On the C5 it can look like this

Yes that was my first thought but since I can't find a resistor pack, and the motor unit contains lots of electronics, I am guessing that this model (C5 Exclusive) doesn't have one! Looks like a good source though, they seem to have things in stock!

[KennyW]

Have you checked your blower control module ?
It is separate from the blower itself.
Will try and find a pic.
Kenny

[Clogzz]

[sjc204]

I think this is where the resistor pack would be - right-hand side of the heater unit, close to the bottom of the steering column (right-hand drive).

[sjc204]

Have you checked your blower control module ?
It is separate from the blower itself.
Will try and find a pic.
Kenny

Are you referring to the resistor pack? I am fairly convinced there isn't one. There are a lot of electronics in the fan motor itself which I think must regulate the motor.
I have looked at the control panel with push buttons for heater control. Nothing looking burned or damaged, but i have no idea how to test it.
Any pointers/ pictures would be great, thanks!

[KennyW]

As per Paul C5's post the module looks that and it is below the blower unit. In my C5 (2010 model) it was in the passenger side of the heater unit.

Kenny

viewtopic.php?t=66786

Have a look at this link which may have some relevant info, this from my C5 x 7.

[dulenator]

I had the same problem, and it was the blower motor. Bought a good used one, and solved the issue! The old one just decided one day to stop working.
There was no strange smell or any traces of something burnt. I suppose the rotor windings just failed.

[sjc204]

As per Paul C5's post the module looks that and it is below the blower unit. In my C5 (2010 model) it was in the passenger side of the heater unit.

Kenny

viewtopic.php?t=66786

Have a look at this link which may have some relevant info, this from my C5 x 7.

Thanks, very helpful, but the heater unit looks different in my facelift C5 from your C5X7. I can't find anything like the Blower Motor Control Unit that you have in yours. I think to be sure I need to find a wiring diagram for my exact model....

[sjc204]

I had the same problem, and it was the blower motor. Bought a good used one, and solved the issue! The old one just decided one day to stop working.
There was no strange smell or any traces of something burnt. I suppose the rotor windings just failed.

Thanks, I am tending toward this view, but trying to check everything I can before I spend £100!

[dulenator]

Yeah, that's a bit steep. I got mine for less than 30€, so it was not an expensive gamble.

[KennyW]

Can you confirm the part no of your blower as I have a spare unit which I don't need.