Thanks that diagram is very helpful I should be able to work it out from there, it actually looks pretty simple.

i just ripped a tacho out of a sporty 120y coupe, i took photos on my phone of how it was hooked up, they aren't very clear, but if you want them pm me your mobile and i'll send them to you, its not very difficult.
should be hooking mine up soon, give me a yell and let me know how you went
cheers and good luck
ty

They are connected to wires that split the ignition feed wire from the ignition switch to the ballast resistor. The cars with Tachos may have a special loom. There were at least 4 different dash looms for B110, B120 over the years.

The wiring diagram shows the tach clearly.
1200 Wiring Diagram

I am trying to remove the clock and put a 1200 sedan tacho in. I have been reading some other threads and some of it makes sense but I'm still a bit confused about where to connect the wires. On the tacho there is:

-a red wire with a female connection
-a black wire with a male connection
-two white wires looped with plug and two spade connections inside

Where do these connect ?

thanks