Negative lead location on distributor, 360la engine, for tach green wire

[73Polara360]

Anyone have a photo or know off the top of their head where the negative lead is? I believe I'm supposed to pass a green wire from my tach through the firewall and attach it there. Anybody have any photos? All I can find are pictures of aftermarket equipment and I am a beginner and don't really know what to look for.

 

[Big_John]

Anyone have a photo or know off the top of their head where the negative lead is? I believe I'm supposed to pass a green wire from my tach through the firewall and attach it there. Anybody have any photos? All I can find are pictures of aftermarket equipment and I am a beginner and don't really know what to look for.

I think you mean the negative on the coil. Since your handle is "73Polara360", I'll assume that's what you are working on. That has electronic ignition, so the wiring to the distributor runs through the ECU (electronic control unit) and you really don't want to screw with that wiring too much.

Every tach I've ever hooked up, including cars with electronic ignition connected to the negative terminal on the coil.

If your car has stock wiring, you want to connect to the terminal marked "-" on the coil and should have a black with yellow stripe wire attached to it.

 

[73Polara360]

I think you mean the negative on the coil. Since your handle is "73Polara360", I'll assume that's what you are working on. That has electronic ignition, so the wiring to the distributor runs through the ECU (electronic control unit) and you really don't want to screw with that wiring too much.

Every tach I've ever hooked up, including cars with electronic ignition connected to the negative terminal on the coil.

If your car has stock wiring, you want to connect to the terminal marked "-" on the coil and should have a black with yellow stripe wire attached to it.

This guy?

 

[Big_John]

This guy?

View attachment 722418

Yep

 

[73Polara360]

Yep

It's working, thanks for your help you led me straight to the right spot. I have a crisp signal and the tach didn't float or lag.

One more question. I will consult my shop manual but does anyone with "the knowledge" know offhand which open sockets ACC vs. battery, so I don't drain my battery, and which would be a good for the white light wire?

Of the three clustered top center, the right-hand one on its own beside the other two gave me power a moment ago. Tried a multimeter but I'm poor at using those I couldn't get a good result so I just tried plugging it into random plugs while car was on and that one gave me power. Is it safe to keep plugged in?

Thanks!

 

[Meltshop Mikey]

I just did this on my 71. I don't know if the dash wire harnesses are similar, but if you look under the dash above the fuse block there may be a yellow connector with three openings hanging around the steering column. My shop manual has this labeled as a connection for the tach power. I clamped on a bullet terminal and plugged it in. Works perfectly and hides the wire.

 

[Big_John]

It's working, thanks for your help you led me straight to the right spot. I have a crisp signal and the tach didn't float or lag.

One more question. I will consult my shop manual but does anyone with "the knowledge" know offhand which open sockets ACC vs. battery, so I don't drain my battery, and which would be a good for the white light wire?

Of the three clustered top center, the right-hand one on its own beside the other two gave me power a moment ago. Tried a multimeter but I'm poor at using those I couldn't get a good result so I just tried plugging it into random plugs while car was on and that one gave me power. Is it safe to keep plugged in?

Thanks!

View attachment 722422

Your circled spots won't work.

The quickest and easiest is marked with a yellow arrow, but there's already something plugged in.

If you pull the fuse block out a little and flip it over, you can tie into that same terminal. Be sure to use an inline fuse in any add on power wiring.

You may have to use one of these "piggyback" spade connectors. Get them at any good parts store.