what is the best way to tap into the negative side of the coil for aftermarket tach?

[MustangNJ]

I am adding an aftermarket tach.  the factory tach works fine, just hard to see.

I expected to find studs with a nut on the coil, but it uses right angled pressure fit caps.  with a stud and nut, adding a tach wire would be easy.  I'm not sure the best way to tap the neg wire with these pressure fit caps. any ideas?

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[midlife]

A ring connector and a very thin nut so the 90* connector can still slip on. Or...you can tap into the wire with the 90* connector that goes to the distributor.

 

[Don C]

There used to be a short wire adapter for connecting tachometers to Ford coils. They were about an inch long with a ring terminal on one end and a male bullet connector on the other end. The ring terminal and a ring terminal on the lead from the tachometer connected to the stud on the coil, and the 90° push on connector went on the male bullet connector. If you want to make one I would solder both the ring and bullet connectors to the short wire and then use waterproof heat shrink on them.

There also used to be a kind of spring push on fork terminal that was thin enough to go under the 90° connector. I looked in my assortment of wire terminals, thought I might have one, and online, but no luck.

I prefer good connections and would cut off the 90° terminal, solder on a ring terminal to the coil wire, no chance of it coming loose, then.

 

[MustangNJ]

there are these right angled friction fittings used all ready the car....the other I found today by accident, aka the neutral safety switch ...I prefer nuts and bolts. these things are old and don't stay put

 

[Don C]

They were an assembly line thing, much faster to stick one of them on than have to dig a nut out of the bin and thread and tighten it.

 

[Hemikiller]

A ring connector and a very thin nut so the 90* connector can still slip on.  Or...you can tap into the wire with the 90* connector that goes to the distributor.

Used this method many times, works great.

 

[MustangNJ]

i used a ring fitting but it was not tight enough to the coil stud at first so I crimped it in place. the factory friction fitting still has plenty of bite.