73' Charger Rally Tach Wire Qestion...help me....

[BMOTOXSTAR]

OK,
So I swapped out my 73' Charger Rally Cluster, non tach. I installed a 71' Charger Rally Cluster with tach.
Question is,
on the back of the tach, what wires go where?
Neg to coil?
Then Red to power accessory?
I do not have the factory tach harness si I figure it is simple 2 wires.
Which posts on the back of the tach are neg & pos?
Thanks all. I am ready to install, just wondering how to wire the tach

[nascarxx29]

A basic tach connection should be on one of these diagrams

1 wire is key on fuse box and one goes to neg - side of coill for tach to read

http://www.mymopar.com/index.php?pid=18

[70 500]

just hook it to one terminal and if it doesnt work swap it over, first time i installed a tach in my old 75 power wagon the coil was labeled backwards and i ended up putting it on the "pos" side to get it to work

[BMOTOXSTAR]

Installed and it works great.
Wow, it is really cool to have a factory tach.
Thanks for all the help guys.