As my tittle says I'm not able to find the tach wires into the engine bay of my 72 240z.

The previous owner installed a mallory ignition system (Mallory Unilite distributor + Mallory Hyfire 6AL ignition) but did not take care of the tach wire.

The wire I'm looking for should be a black and white wire which should have been plugged to the coil when the car was stock.

On the following wiring diagram, we can see which wire I'm talking about

I doubt the previous owner cut or removed the wire when he did the swap. Where does this cable go????

I've tried to see if I can find this wire by following the harness from the cabin with no luck. Where should this wire be?

Can someone look at his stock setup?

I've taken picture of my system, There's one black/white cable but it's plugged to the red ignition system wire, so I assumed it's ignition wire and not the tach.

The car is working absolutely fine, I assume everything then is okay. I just need the rpm tach to work...

(I do not like how the wires are tapped, I'm going to change that soon Don't pay attention then :cheeky: )

Thanks!

I've made a post as well on HybridZ with the diagram for the mallory system fyi.

http://forums.hybridz.org/showthread.php?p=825065

In addition to my previous post, I've made a pic of my tach. We can clearly see a yellow/red wire which is not mentionned into the wiring diagram (it should be green) I do not see neither the white an dblack wire I was talking about...

I'm confused

That's almost an easy question Lazeum. You need a "Tach Adaptor" Both Mallory and MSD make one. The tach in the Z's have a resistor and it makes it tough to get a tach to work after installing an electronic box like MSD 6A or the Mallory.

The red 2" X 2" box above my MSD 6A is an MSD tach adaptor. Summit and Jegs sell them. Jegs part number is 121-8910 and it's about $50

I've already got the tach adapter. It's not installed yet.

I have the mallory tach adapter which is very similar to the MSD 8910.

My real concern is where to find under the hood the correct cable to plug the tach wire from the mallory ignition unite. (the yellow one on the picture)

Thanks for your anwser btw

I believe the all metal box is the resistor. In my Z, it takes a green wire and a black and white wire. One is from the tach the other is from the ignition switch. Hope that helps.

Rich

I assumed it right then, the tach seems to be fixed for now.

Everything seems to work very good for now in my garage in neutral, It's snowing now, I'll have to wait to make sure everything is OK and test it on the road.

It's good to see stuffs moving forward

I basically did not change anything on the current setup, I've just add the adapter between the white/green wire and the red one.