Jump to content


Photo
- - - - -

Ignition signal from engine compartment to tach...


  • Please log in to reply
15 replies to this topic

#1 marinez

marinez

    Moving Up

  • Members
  • PipPip
  • 42 posts
  • LocationSalem, Or

Posted 30 August 2016 - 01:49 PM

Ok...10/75 280z. 327 with HEI. Tach has been recalibrated, now trying to hook up correct wires. Have brown, green, red under hood at former distributor harness. Prior owner used black/white for coil power, 12v ignition hot. Thoughts?

#2 NewZed

NewZed

    Clandestine Moderator

  • Members
  • PipPipPipPipPipPipPipPip
  • 5209 posts
  • LocationWashington County, Oregon

Posted 30 August 2016 - 02:46 PM

Brown, green and red would be the VR sensor wires that run to the ignition module in the cabin.  The blue wire from the coil negative terminal (through the ballast) is the tach trigger.



#3 marinez

marinez

    Moving Up

  • Members
  • PipPip
  • 42 posts
  • LocationSalem, Or

Posted 30 August 2016 - 02:49 PM

I might have to hug you.

#4 marinez

marinez

    Moving Up

  • Members
  • PipPip
  • 42 posts
  • LocationSalem, Or

Posted 30 August 2016 - 03:15 PM

Well...nothing.

#5 NewZed

NewZed

    Clandestine Moderator

  • Members
  • PipPipPipPipPipPipPipPip
  • 5209 posts
  • LocationWashington County, Oregon

Posted 30 August 2016 - 03:20 PM

No hug?

 

You need to add some detail.  There are some considerations and some simple tests you can do.  It's not even clear what you mean by nothing.  Could mean no blue wire, could mean blue wire doesn't work.  Could be the resistor fell out.



#6 marinez

marinez

    Moving Up

  • Members
  • PipPip
  • 42 posts
  • LocationSalem, Or

Posted 30 August 2016 - 04:59 PM

Sorry Zed. No signal from the blue wire. Any idea what the end connector might look like? I just found another blue wire.

#7 NewZed

NewZed

    Clandestine Moderator

  • Members
  • PipPipPipPipPipPipPipPip
  • 5209 posts
  • LocationWashington County, Oregon

Posted 30 August 2016 - 05:17 PM

Do you know what the signal is?  Did you measure voltage at the tach end of the blue wire?  Have you looked at the wiring diagram?

 

Really, the basics are pretty easy with a meter.  Get everything connected correctly, then you can focus on why the needle doesn't move.  With a meter you don't have to worry about what the terminals look like.

 

Who recalibrated your tach, and is it the stock 1975 280Z tach?  Are you using the stock 280Z harness connection at the tach?  Aftermarket tachs can have different wiring schemes.



#8 marinez

marinez

    Moving Up

  • Members
  • PipPip
  • 42 posts
  • LocationSalem, Or

Posted 30 August 2016 - 05:27 PM

Stock tach with pot reset.Stock harness at rear of tach.

#9 marinez

marinez

    Moving Up

  • Members
  • PipPip
  • 42 posts
  • LocationSalem, Or

Posted 30 August 2016 - 05:30 PM

Shoot. I forgot to ask what the correct voltages should be.

#10 NewZed

NewZed

    Clandestine Moderator

  • Members
  • PipPipPipPipPipPipPipPip
  • 5209 posts
  • LocationWashington County, Oregon

Posted 30 August 2016 - 05:51 PM

With the key On you should see battery voltage at the tach end of the wire if it's connected to the coil negative terminal as it should be.  The 280Z tach just counts the voltage pulses on the negative post of the coil as the coil charges and discharges.



#11 marinez

marinez

    Moving Up

  • Members
  • PipPip
  • 42 posts
  • LocationSalem, Or

Posted 30 August 2016 - 06:07 PM

Ok so remember this is HEI. Big cap.

#12 marinez

marinez

    Moving Up

  • Members
  • PipPip
  • 42 posts
  • LocationSalem, Or

Posted 30 August 2016 - 06:09 PM

Crud.. ok...so essentially I have to connect the HEI to the factory harness. I'm concerned the tach itself isn't receiving power.

#13 NewZed

NewZed

    Clandestine Moderator

  • Members
  • PipPipPipPipPipPipPipPip
  • 5209 posts
  • LocationWashington County, Oregon

Posted 30 August 2016 - 06:28 PM

There's a tach output terminal on the typical HEI distributor from what I see on the old interweb.  It's probably just a branch from the coil negative post.  Easy to check.



#14 marinez

marinez

    Moving Up

  • Members
  • PipPip
  • 42 posts
  • LocationSalem, Or

Posted 30 August 2016 - 06:50 PM

That's live and working.

#15 NewZed

NewZed

    Clandestine Moderator

  • Members
  • PipPipPipPipPipPipPipPip
  • 5209 posts
  • LocationWashington County, Oregon

Posted 30 August 2016 - 06:55 PM

I don't know what means.  But, good luck with it.  

 

I have a GM HEI system, module and coil, on my L6, using the 280Z VR signal.  My tach doesn't work without a condenser on the negative terminal wire.



#16 marinez

marinez

    Moving Up

  • Members
  • PipPip
  • 42 posts
  • LocationSalem, Or

Posted 30 August 2016 - 07:08 PM

Ok...I just need to establish if the tach has power. I have signal from the hei.




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users