Fixed the speedometer, got to looking at the circuit diagrams and it showed four wires for connections.

Pulled the speedometer and only three were hooked up!!! After tracing wires the missing wire was the power wire, fished around in the dash and couldn't find anything that looked like it would reach.

Anyway the previous owner stated that it used to work, but hasn't for the last couple of years, so a bit mystified as to how it could have previously functioned without a power wire.

Provided a replacement power wire and it immediately started working again.