Thanks for all the info guys. Think I'll be going down the garage tomorrow to got through what's been said and if needs be get an auto electrician I know to have a look into it before forking out for a new fan.
Being a bit naive here... is Jules on the MGOC site? At work on mob atm and not got my membership number to login to see.
Right been down the garage and sadly it's the 3 speed fan variant in mine so the resistors not an option.
So rather than drag things out and for peace of mind I think I'll bite the bullet and contact Jules for the new 2 speed fan motor and resistor.
Thanks for all the info everyone. You've still prob saved me £200 with the links provided than had I just let the garage sorce one from their suppliers.