1966 Barracuda Formula S tacho wiring

[AussiePlymouths]

My Tachometer has stopped working in my Formula S.
It was working fine previously.
my Service Manual wiring diagram shows the wiring for the vacuum gauge, but not the tacho.
Would anyone be able to tell me what wires come from where to the tacho please ?
or better still a link to a wiring diagram for the Tacho please?

I looked online but found nothing

TIA
Gary

 

[Super-Cuda]

My Tachometer has stopped working in my Formula S.
It was working fine previously.
my Service Manual wiring diagram shows the wiring for the vacuum gauge, but not the tacho.
Would anyone be able to tell me what wires come from where to the tacho please ?
or better still a link to a wiring diagram for the Tacho please?

I looked online but found nothing

TIA
Gary

Try here.

Wiring Diagrams

Also, you can upgrade it to modern electronics for use with electronic ignition.

See here.

https://www.rt-eng.com/images/8/8f/TachBoardManual_REV8.pdf

 

[FISHYPETE]

The sending unit for tachometer is by or behind drivers side kick panel

 

[4mulas]

I had that’s same car and it’s likely your tach that quit. Only wire I remember off hand is grey to the negative side of the coil.

Regardless contact or google ‘ rt-eng ‘ and ‘ 66 barracuda tach ‘ and you’ll find some good info there. They make a replacement digital tach to go inside the original housing (which I think was tucked under the drivers side lower kick panel?

Where in Aussie?

Good luck

 

[cudamark]

My Tachometer has stopped working in my Formula S.
It was working fine previously.
my Service Manual wiring diagram shows the wiring for the vacuum gauge, but not the tacho.
Would anyone be able to tell me what wires come from where to the tacho please ?
or better still a link to a wiring diagram for the Tacho please?

I looked online but found nothing

TIA
Gary

The tach wire at the bulkhead connector is in cavity M....center connector the bottom hole farthest from the bulkhead index pin. Gray with a black tracer. It goes to cavity 2 in the tach sender connector. Cavity 4 has a violet wire with white tracer coming from the wiper switch power supply. Cavity 3 is a yellow wire going to the tach. Cavity 1 is empty. Oh, and there is not wiring for the vacuum gauge....just a hose.

 

[AussiePlymouths]

thanks for the diagrams link, but I still don't see the tacho, I must be blind

And I am sorry, have already installed, years ago, a solid state box to replace the original can (I should have said that in my post )

 

[AussiePlymouths]

The tach wire at the bulkhead connector is in cavity M....center connector the bottom hole farthest from the bulkhead index pin. Gray with a black tracer. It goes to cavity 2 in the tach sender connector. Cavity 4 has a violet wire with white tracer coming from the wiper switch power supply. Cavity 3 is a yellow wire going to the tach. Cavity 1 is empty. Oh, and there is not wiring for the vacuum gauge....just a hose.

Thank you, that is exactly what I was looking for. appreciate your reply

Would you happen to know where that gray wire w/black trace actually originates from to link to bulkhead connector M please?

 

[Mattax]

Factory tachs work off the pulse of coil negative.
At least in '67 they needed a 12 V power source that came from the auxilery/optional fuse.

Go to mymopar.com
Find the section that says Service Manuals.
Download the 1966 Plymouth Chassis manual.
In the back of the electrical section you'll find the wiring diagrams.

Looks like in '66 power comes from a terminal junction on the wiper switch.

 

[Mattax]

This without the tach.
The tach harness modifies this as shown in the inset posted in the previous post

 

[AussiePlymouths]

Factory tachs work off the pulse of coil negative.
At least in '67 they needed a 12 V power source that came from the auxilery/optional fuse.

Go to mymopar.com
Find the section that says Service Manuals.
Download the 1966 Plymouth Chassis manual.
In the back of the electrical section you'll find the wiring diagrams.

View attachment 1716388867
Looks like in '66 power comes from a terminal junction on the wiper switch.

Thank you sir, I will follow up!
As always I appreciate your input

 

[AussiePlymouths]

I had that’s same car and it’s likely your tach that quit. Only wire I remember off hand is grey to the negative side of the coil.

Regardless contact or google ‘ rt-eng ‘ and ‘ 66 barracuda tach ‘ and you’ll find some good info there. They make a replacement digital tach to go inside the original housing (which I think was tucked under the drivers side lower kick panel?

Where in Aussie?

Good luck

Thanks mate, I am in Outer Western Sydney NSW

 

[AussiePlymouths]

Thanks mate, I am in Outer Western Sydney NSW

So where are you ?

 

[4mulas]

Canada. I’ve travelled your parts for a year once and am always curious where folks live. I started in the north, went down the east coast, across the Nullabor in a train then back Melbourne

 

[AussiePlymouths]

Canada. I’ve travelled your parts for a year once and am always curious where folks live. I started in the north, went down the east coast, across the Nullabor in a train then back Melbourne

Sounds like a great adventure! You are ahead of me, I have seen very little of my own country, the Nullabor would be really something.

 

[AussiePlymouths]

Well the problem is solved THANK YOU to everyone who offered advice.

Simple fix (thankfully) the grey w/black trace wire had come off the negative post on the coil.

After reading all of those helpful comments that was the first thing that I checked, so fixed in a few minutes with a new terminal on the wire. So good to see that needle dancing

I really appreciate all of the help that I get on FABO, so many "giving" people on here!

I owe you all a cyber beer!!!