VDO Tach Wiring

[siii8873]

I have a VDO tach with three terminals on the back that I want to install. The terminals are as follows, am I correct as where to wire this up;

+ switched power from the ign switch
- Ground
G Negative side of coil (this is the one I'm unsure of)


Thanks
Bob

[disco2hse]

Mostly, I have seen them attached to the W post on the alternator: like this.

http://i275.photobucket.com/albums/jj287/naskeet/VDO-Alt-W-Tach.jpg

This indicates three types, so which is yours?

http://www.aircoolednut.com/erkson/ttt/electrical/tachometer_wiring-1.jpg

[siii8873]

the back of mine looks like the middle left one on the top diagram. I'll have to check the back of my LUCAS alternator to see if it has a "W" terminal.
thanks

[busboy]

Mine is just off the neg on the coil, don't know the tach manufacturer though.