A70Supra elec Speedo help

[Supra|boy|]

OK so i sold my car a few weeks back and the guy who bought it wants to try and get the speedo working again.
Now it has a a340e from an aristo with a splined output shaft.
I have just put a plate on the speedo output hole as the mechanical one didn't fit.
So the question i need answered is.
How do i get the elec speedo output from the a340e's to work on the a70supra mechanical digi dash.
Cheers

[VA61DETT]

G'day

I interfaced my Nissan electronic gearbox sensor to an MA61 cluster with a very simple circuit.

In my case the Nissan box has a magnetic pickup, which generates a sawtooth looking wave form which varies frequency (and voltage) depending on speed. I capacitor and 5v zener diode in such a way as to pass the pulses but also provide clamping as not to damage the dash input (as the generated voltage spikes ramped up to >30 volts pkpk).

On the dash side you will need to remove the mechanical 'chopper wheel' and locate the appropriate signal pin from the opto assy.
I just fed my filtered output straight into the dash & it worked a treat.

If you can provide details on the gearbox / dash setup I can prolly draw up the circuit for ya.

-A