doblo fan switch

[john le taxi]

Hi all i,m new to the site really enjoying it but having trouble finding my way round.I drive a 05 2005 doblo 1.9jtd which is a taxi in middlesbrough.I have done 163k trouble free miles but now my heater fan blower will only work on full (no 4) i was wondering if anybody knows what the problem is and how much the part is and is it easily replaced

 

[maddogmorg]

sounds like a failed resistor pack, other than that no idea.