1971 stock tach + Pertronix II

[dewiant]

Hi guys,

I know that this topic has been repeated many thimes on this forum... Tried to read all the topics but mostly those are mess or doesn't really applies to my configuration.

1. I'm trying to restore my factory tachometer (after previous owner butchered it and cut off the cables at the back).
2. I have found the wire under the hood, where the coil (+) should be plugged - as I understood from wire diagrams, this is a wire which (in theory) goes from tachometer, via Pink Resistance Wire, to coil. It should be around 6-8V but for me it's over 11V so I guess that previous owner butchered that pink wire as well.
3. I have Pertronix II with Flame-Thrower coil (1,5 Ohm) connected directly to battery (with a switch which enable power only when the engine starts and is running).


This combination works properly (I can start the engine, it works fine while driving, no issues) but the tachometer is not working (since it's not connected at all).
I'll try to restore it and weld proper wires to it as well, and when its done, I would like to try to make it work

And here are my questions.
I was planning to follow a graph below.
4. Should that work for me?
5. Do I need to restore the pink resistance wire as well (even if the coil has to be powered with 12V (not 6-8)?
6. Is there anything I should be paying attention to especially?



Many thanks for any suggestions!
Cheers!

 

[72mokk1]

I have the same set up but much older (30 years) with the same butchered wiring harness. I restored the pink resister wire and my engine and tach run fine. My Pertronix was for a dual point distributor is the only difference I see.

 

[dewiant]

I have the same set up but much older (30 years) with the same butchered wiring harness. I restored the pink resister wire and my engine and tach run fine. My Pertronix was for a dual point distributor is the only difference I see.

I'm planning to restore Pink Wire as well, then connect it to coil (in addition to already connected battery).

My question is, will that be enough? Or do I have to terminate the connection to battery, and make the connection to wire between tacho and ignitation switch (like on the picture)?

 

[rhigg1959]

I had the same issue on my tach after installed the Petronix II. I watched a video by Jeff at Restomod on youtube and he explains
how to wire to fix this. My harness was complete to my tach. I bought a trailer wiring harness extension and connected between the harness
and the tach and ran a splice from the red wire direct to the + of the coil and the tach worked fine. Just like the picture you provided.

 

[dewiant]

I had the same issue on my tach after installed the Petronix II. I watched a video by Jeff at Restomod on youtube and he explains
how to wire to fix this. My harness was complete to my tach. I bought a trailer wiring harness extension and connected between the harness
and the tach and ran a splice from the red wire direct to the + of the coil and the tach worked fine. Just like the picture you provided.

Thanks, I'll check that video out!

 

[72mokk1]

I had the same issue on my tach after installed the Petronix II. I watched a video by Jeff at Restomod on youtube and he explains
how to wire to fix this. My harness was complete to my tach. I bought a trailer wiring harness extension and connected between the harness
and the tach and ran a splice from the red wire direct to the + of the coil and the tach worked fine. Just like the picture you provided.

Do you have a stock tach? And how long have you been running the car in this configuration? Out of curiosity I ran a pig tail from the electric choke to the coil, it did seem to start quicker but I noticed the tach reading was lower by 2 to 4 hundred RPM with the hot wire connected and higher disconnected. My concern was burning up the stock tach.