F28 gearbox / speedo issue

[--ToM--]

hi chaps im running an f28 hearbox in my mk2 gte the speedo has decided to stop working it just shows 0 mph on the dash constantly, what should i be looking for?

[Pitstoppete]

are we talking digi dash here?

if so is the wiring still plugged into the speedo sensor on the gearbox?

or have you got a std style dash, has the speedo cable broken?

[--ToM--]

digi dash mate and the wiring is still plugged in so is the speedo mech, the clocks light up as normal just show 0mph constantly

[Pitstoppete]

unscrew the gearbox transducer, jack car up, run it to see if the square speedo drive bit is turning.