Speedo problem

Hi all

I have an issue with my fiesta, it had a 1.7 swap which was working like a dream, it was then swapped for a cammed 1.7, the engine was the only thing changed, ECU, loom & gearbox were all the items I already had on the car however since its all been put back together the speedo isnt working, I've swapped the sensor over to no avail the clock test shows all needles working fine but no reading whilst moving, does anyone have any ideas of what else to look for to see what could be causing this?

Is it an analogue or digital dash?
If it's digi dash, try and get someone with a scangauge or obd2 interface. That will at least tell you where the issue is, if the OBD2 is picking up a signal then the problem is your signal to the speedo. There is a triangular plug that comes off your speedo transducer, it has a signal wire from memory it's brown, and that goes from your transducer and splits, going to both the ECU and the speedo head. If neither are getting signal, then check the transducer has power, it should have one 12v input (or it could be 5v). If it has all the correct voltages, unscrew it from the box, and put it in a drill and turn (with ignition to position 2) & see if the speedo goes up. If not it's likely your speedo transducer.

If the speedo does work with a drill, then you've possibly worn the teeth on the nylon cogs that attach to the diff or the worm gear that it spins.