Heater Blower Motor Working Intermittently

Hi Forum

I have a 2011 C4 Grand Picasso VTR+ HDI.

The Fan Blower works intermittently. Actually works it works very little - only coming to life for a minute or two very very occasionally.

I have purchased and installed a Heater Blower Motor Resistor as the original looked pretty corroded. I thought that would fix the problem but my joy was short-lived. The fan only worked briefly.

Any suggestions for the next step? A new Fan perhaps?

Thanks
Pete