Im pretty sure it works just can get it going. Am i right in thinking you need a feed from the positive side of the coil that goes to the positive terminal at the back, then earth the negative terminal?

Jon boy I am running one have a look at the following courtosey of etb instruments.

80mm

http://www.etbinstruments.com/ETB_Gauge_Wiring_PDF/80mmETB_tachometer.pdf

or

100mm
http://www.etbinstruments.com/ETB_Gauge_Wiring_PDF/100mm_ETB_Tacho_wire.pdf
followed this and mine is working

regards

agriv8

[Edited on 12/1/06 by Agriv8]

Cheers mate, i'll give it a crack. I can see where i went wrong already! THank you!

With a VDO Tach,
2. pos supply from ignition switch via fuse.
3. earth
4. negative side of coil
You will also have three switches on the back for setting cylinders.
4 cylinders 1-on 2-off 3-off

(Thats assuming you have a tach with 8 terminals on the back as well as the two instrument lights)

[Edited on 12/1/06 by Dusty]

Found a pic
Rescued attachment vdo.jpg