Does anybody have any diagrams/info on how this gets hooked-up?? I have the speedometer, speed warning cable, wire harness and what looks to be a relay or buzzer mounted on top of the speedo.
Just trying to figure out how this thing wires in...

Thanks,
Mike

Mike see Fig 15-15 in the '68 Pontiac Service Manual. http://1968firebird.org/68sm/acc/acc2.html
It might be what your looking for. I suspect that's a fairly rare option. I don't hear much about the Safeguard Speedometer.
Jim