I wonder if you caught it in the act of burning out then, gradually failing over a shortish period of time, is there any sign of damage, looking at the old one? 

Have you got a multimeter you could stick on the middle two pins (2 & 3) of the resistor pack, on an Ohms/resistance range?

Have you got a multimeter you could stick on the middle two pins (2 & 3) of the resistor pack, on an Ohms/resistance range?

 Put a meter across it and there is no continuity across pins 2 and 3, Metered the others - not sure what to expect but - 1 to 2 nothing, 1 to 3 continuity, 1 to 4 continuity, 3 to 4 continuity. No visible sign of damage. 

 Put a meter across it and there is no continuity across pins 2 and 3, Metered the others - not sure what to expect but - 1 to 2 nothing, 1 to 3 continuity, 1 to 4 continuity, 3 to 4 continuity. No visible sign of damage. 

Nice one, cheers for that. Consistent with the bit of resistance wire that I've labelled R1 in the circuit up there ^ no longer connecting pins 2 and 3.  I guess that could be the connection at either end of that winding, or a break somewhere along its length.

 

When did you last treat yourself to a new pollen filter? That being clogged up will reduce airflow over the resistor (and into the cabin!), and increase the chances of the new one burning out.

My fan stopped working on setting one last night - what is the part number for a new resistor pack?

My fan stopped working on setting one last night - what is the part number for a new resistor pack?

 

  6Q0959263A

Anybody any pics or 'How to's' for the resistor change.....my fan is only working on settings 2,3 & 4 ?

https://www.briskoda.net/forums/topic/178661-fan-only-works-on-higher-speeds/

 

/\ I’ve used this guide. 

 

FYI I had to get my missus to get in there as mine were too big. As the above guide suggest, there’s little room to turn it and pull out. 

I used a slotted screwdriver to push the resistor housing round. You can push a little dent in the edge of the plastic to grip with.

Looking at postson here, one thing comes to mind- DRY JOINTS on connections. I've had this on telecomms circuits in past- and only way to find it was to look for it with a low level signal. One reason why in old days pre decessors of BT would use a "wetting" current on private datacircuits ( other  than to stop jointers "assuming " that a no volts circuit was not live.) (Bit of history education for any Openreach jointers on here).

On dry joints, the circuit became Open circuit, till a stronger signal was passed over it, when the dry joint ceased and full contact was made .

Then again, soldered joints can fail through age with granulation of the joint, or extremes of temperature, creating a dry joint effect. One reason why high powered transmitter circuit joints in military radio use a more "plumber" type of solder, and again why BR changed from solder type track connections ( for track circuit train detection) to crimp connectors, as solder joints failed in low temperatures.