F11 - Blower motor relay fuse - no power

[GilesO]

2009 XTR

Tracing fault on blower motor.
Pinned down to F11 12v supply - no power when vehicle ignition is on.

Relay, blower and controller work fine when F11 is bypassed (direct 12v feed into fuse connector).

Where does F11 get its feed from? 
(I am assuming its from the main feed into the engine bay fuse board, but as it is "ignition on" dependent, it has to be a switched feed). 

Any ideas?

[Sol]

That fuse is powered by another fuse, MF4 (MasterFuse 4) which is in the bottom section of the engine bay fusebox, under the top visible layer. You need to remove the top tray (may be rivetted in place) and the you can access the MasterFuses. They swing out once the top layer is removed. MF4 only powers F11.

   

[GilesO]

That fuse is powered by another fuse, MF4 (MasterFuse 4) which is in the bottom section of the engine bay fusebox, under the top visible layer. You need to remove the top tray (may be rivetted in place) and the you can access the MasterFuses. They swing out once the top layer is removed. MF4 only powers F11.

Thanks for that.

The Haynes manual diagram wasn't very helpful as it shows F11 directly powered from the battery with M4 and M5 parallel to - not in series with - F11...

[Sol]

I took this from the official schematics in Citroen ServiceBox. Haynes is good, but it lacks locations for relays and the masterfuses, I only used the Haynes diagram to show the position of that fuse.

I've attached the official schematic below - follow F11 back to MF4.


  B9_Heating.pdf (Size: 157 KB / Downloads: 31)

[GilesO]

I took this from the official schematics in Citroen ServiceBox. Haynes is good, but it lacks locations for relays and the masterfuses, I only used the Haynes diagram to show the position of that fuse.

I've attached the official schematic below - follow F11 back to MF4.

Thanks very much.

MF4 was OK but contacts looked pretty manky. Cleaned them up.
Decided to remove fuse box and all fuses, cleaned them up.

Everything now works as it should. 

Now need to sort rattle in the blower. There’s always something…

[Sol]

That's good to know. Could be a fix for other issues going forward.

The blower mounting bolts are 5.5mm heads, but Halfords sell a little socket set with that size in it..

[GilesO]

Thanks again.

Found out about the bolts the hard way...
Finally got them off with an adjustable and replaced with automotive philips head self-tappers to make life easier in future...

On my model, the blower bottom bearing has a removeable cap, enabling lubrication. Also used the silicone lube flexi-pipe to get under the moulded fan and spray the front of the shaft as it emerges from the motor.

Now the fan can only be heard on setting 4 - whisper quiet on other settings.
I'll call that a result. At least until it does it again...

[Sol]

I did a similar thing last year on my previous B9, and a new resistor.

A tip which I think causes the failure of the resistor, is by crap design, it is in the outlet airflow for it's cooling and not the intake on the B9, so when you have the blower on low speed and the heat setting up high, the resistor is working at its hardest, and being "cooled" by very hot air. Not a good combo. So when mine is up to temp, I always put the heat setting back to the first "gap" between the last red band and the previous red band, and no more.