Sorry - I was posting while distracted and didn't get to my end point
 A new speedo is a lot more forgiving so you'd likely not have noticed the issue with the routing, with an older one they're much more sensitive and sometimes its just not possible to get the cable routed in a way that will work.
  A new speedo is a lot more forgiving so you'd likely not have noticed the issue with the routing, with an older one they're much more sensitive and sometimes its just not possible to get the cable routed in a way that will work.