speedo needle jumping

[Albert Herring]

Can't help with the electrical bit, but if you've had the front brake caliper off, check the sensor cable for damage first - there is an easy to make* error when refitting the caliper that leaves the cable liable to foul the brake disk, which produces the berserk needle thing on the speedo; however, the correlation with the indicators suggests it's probably the electrics.

*I found it easy, but I'm a bit of a mechanical numpty.