Please help me understand ignition wiring & Tacho....

[pharriso]

Bill, thanks for the advice. I did have to add a 100 Ohm resistor between the tacho & the coil -ve.

Working perfectly now, no bouncing! I heartily recommend the Spiyda RVI --> RVC tacho conversion circuit board.

[pharriso]

Fantastic guys!! Funny how there are many posts on how to modify the tacho itself, but very little info on the new input wire required...

To remedy this, here is the original tacho wiring with the RVI Tacho between the ignition switch & anti-theft switch / coil +ve:

And the modified wiring with the Spiyda modified RVC Tacho connectted by a new wire to the coil -ve:

& for completeness I note that I had to add a 100 Ohm resistor on the input of the Tacho.

If I get a spare minute I'll draw these 2 diagrams up in Visio or CAD, but you get the idea...