Rev Counter Polarity

[MINSTER 407]

Thanks David for the JDO link.
Greg, I know a tacho isn't important but it's nice to have working if installed and it would help setting tickover/timing on tickover etc.
The conversion article you included is quite detailed and i had found it , but it's one that talks about the green wire being swapped from earth lug to power lug.....and the RVI 2810/00 just doesnt have a green wire or earth lug next to the power lug - hence the frustration of me and my soldering iron.
I'll measure the face of my tacho and if you have a RVI tacho of the same size in negative earth from a 411 that i can buy from you that may be the easiest answer.
Thanks everyone for your input and suggestions