Tachometer and wiring

[Dcreech0]

Sorry. One more video. Will be my last. Showing what I was finding at the connection behind the tach. 

[SteveJ]

4 hours ago, Dcreech0 said:

Please watch and give some insight. 

IMG_7379.MOV

You missed a key detail in my video. I said ALL the wires were disconnected. You had the ignition wire connected to the ballast resistor along with the green/white wire. That's why you had voltage on the black/white at coil positive.

Anyway, all the wires are connected properly. Post a photo of the back of the tach if it's still out. Let's make sure it's a 240Z tach. It would take some rewiring to mate a later tach to a 240Z, but with the other surprises on your car, we don't know what we're going to find.

[Dcreech0]

9 minutes ago, SteveJ said:

You missed a key detail in my video. I said ALL the wires were disconnected. You had the ignition wire connected to the ballast resistor along with the green/white wire. That's why you had voltage on the black/white at coil positive.

Anyway, all the wires are connected properly. Post a photo of the back of the tach if it's still out. Let's make sure it's a 240Z tach. It would take some rewiring to mate a later tach to a 240Z, but with the other surprises on your car, we don't know what we're going to find.

The tach is the correct tach. I have read as much as I could on them and learned It is the four wire tach with the loop that reads current for the rpm. 

[Zed Head]

On 8/13/2021 at 6:19 AM, Dcreech0 said:

getting my tachometer to work

So, what, in detail, does the tach do and not do?  Does the needle twitch at all when you turn the key on or start the engine?  These old tachometers fail often and in many different ways.  

[Dcreech0]

2 minutes ago, Zed Head said:

So, what, in detail, does the tach do and not do?  Does the needle twitch at all when you turn the key on or start the engine?  These old tachometers fail often and in many different ways.  

It does absolutely nothing. Totally dead

[SteveJ]

When you did the continuity measurement, was the tach plugged in?

[Zed Head]

2 hours ago, Dcreech0 said:

Sorry. One more video. Will be my last. Showing what I was finding at the connection behind the tach. 

IMG_7385.MOV

You should put your videos on youtube.

[Dcreech0]

2 minutes ago, Zed Head said:

You should put your videos on youtube.

I will do that now with all three and post the links for you all

[Dcreech0]

6 minutes ago, SteveJ said:

When you did the continuity measurement, was the tach plugged in?

When doing the continuity tests at the coil and ballast, yes the tach was plugged in. 

[Zed Head]

35 minutes ago, SteveJ said:

You had the ignition wire connected to the ballast resistor along with the green/white wire. That's why you had voltage on the black/white at coil positive.

You might take those measurements again, following SteveJ's instruction.  Make sure that the current is actually passing through the loop.  You could also take a measurement at the tach plug to make sure the voltage is getting to the tach.  Then you'll know for sure.

[Zed Head]

1 minute ago, Dcreech0 said:

When doing the continuity tests at the coil and ballast, yes the tach was plugged in. 

 

Just now, Zed Head said:

You might take those measurements again, following SteveJ's instruction.  Make sure that the current is actually passing through the loop.  You could also take a measurement at the tach plug to make sure the voltage is getting to the tach.  Then you'll know for sure.

If you saw continuity, then never mind.

[Dcreech0]

41 minutes ago, Zed Head said:

You should put your videos on youtube.

https://youtube.com/shorts/d5huZZpAatU?feature=share

https://youtube.com/shorts/qyWt6QMMlF0?feature=share

https://youtube.com/shorts/s3u_VdbvO3c?feature=share