Kev, been there, done that but there is so much confusion about the actual location of the resistor pack, I thought I would ask on here, expecting that there would be many responses. Apparently, this is a common problem on all chassis' built for Peugeot, Renault, Citroen and Fiat and going back to1998!!
So, where was your 2007 version located. If there is enough interest and the location is common, I could post on here how to remedy it. Waiting for the replacement part so I can't confirm yet if it solves the problem?
I've asked on the Fiat Forum for you, on my 07 relay it was to the left below the fan, but within the fan housing if that helps.
See these vids, it all looks very similar to mine.