Finally got my cruise working again (2010 x250), I always thought it was the stalk as it was working with a wiggle until it stopped completely.
I saw a 2012 complete stalk on eBay for £45 and took a chance on it being the correct replacement, it wasn't although it did fit.
Although Fiat only sell the stalks as one unit for around £350 it does separate quite easily. So with nothing to loose I stripped it apart to look.
Inside the cruise arm moves a carrier across the contacts and this had separated from the board.
So I bonded it back on, replaced every thing and it now works as it should.
You can see the carrier in the photo, black with the grey slider.

Hi, I had the same problem (2011 x250). I also removed the stalk from the car and took it apart. Carefully took out the green print board inside the cruise arm. Under the carrier found four copper wires connecting the the carrier to the print board. Just had to straighten them a bit to reconnect carrier and board. Now works ok.

Another picture showing the pins.

Hi Coopersale. How easy was it to get the stalk off. I can't see how it can come off without taking the steering wheel off. Is there an easier way.
Cheers tribby

I did remove the wheel, (and air bag) not as scary as some will tell you.

I got mine off without removing the steering wheel. Took the cowling off under the steering wheel and then the cruise control unit clips out as a separate unit. Have cleaned the connections and will try it out on the weekend.

Up date. Mine worked perfectly after stripping and cleaning the connectors.