This is not for a magna but when u put a tacho in a car without one you just hook it up to the solenoid or something. :doubt: Thats what i gather from listening around anyway. Where on the solenoid?

Do you mean the coil? They usually have a wire that attaches to the coil and then a switch on the tacho to tell it how many cylinders the engine has.

Basic tachos generaly have 3 main wires plus lighting wire/s.
one wire will be power when ignition on +12V
one wire will be earth/body -12V
one wire will be the negative terminal of the coil -.
depending on design it will have one wire for power +12V you need to tap of a dash light or any light that comes on with your parkers, it may also have a seperate earth/body -12V wire.

I was going to give a bit of an explination on how the tacho works but I got to go pick up Mik from work, maybe later if you want.

hey man, if u want detail on how to install a tacho just pm me if u want......?
just dont feel like doing that much typing without u needing it

yeh its easy as a $2 hooker mate, even a girl could probly do it.. :confused: