Where are the relays in the electrical drawings.

[Trimpe.bob@gmail.com]

Hello, I’m a new forum member. I recently picked up a nice 73 240Z that I plan to swap in a later turbo motor. I am new to Datsun and Z, but have been working on vintage cars for a long time! my question is: 

There are several relays mounted at the passenger side kick panel. I cant locate any of these on the electrical drawing I have. See attached. I have looked at several drawings but they are all almost identical. Am I missing a drawing, or a piece? I’d like to ID these relays and understand how they fit into my cars controls. I also have seen mentioned a “power relay”. Where is this on the car, and in the drawings? What does it do?

im looking forward to building and improving a great car, and this looks like the place for info and advice!

regards,

Bob t.

ColorWiring240Z-1973-USA-Manual.pdf

Edited December 24, 2020 by Trimpe.bob@gmail.com

[SteveJ]

Have you looked at the EE section of the 73 FSM? It's available on this website. Go to Resources and then Downloads. Also you probably have found the relays for the factory authorized/designed modification to add the electric fuel pump in the 73. I think the documentation on that is floating around in the downloads section, too.

[Trimpe.bob@gmail.com]

Ah! Thanks, Steve.  I looked at the drawing in the FSM and it is a little more enlightening. (page attached; sorry, couldn’t figure out how to rotate it!) I found the horn relay, ACC relay, rear window defroster relay, throttle opener relay. 
 

im guessing that the ACC relay is the “power relay” I’ve seen referenced?

is there a document that shows the physical locations of these relays?

car does have an electric fuel pump. I am very interested in locating this one before I REALLY need it! I’ll poke around some more in the resources section for this info.  
 

Regards,

bob t
 

 

[SteveJ]

It takes some creative thinking, but BE-3 gives you your guide to mapping out the relays. What the drawing does is show the wire colors going to the connectors. Turn the page sideways and look toward the right side. From the connectors, follow the lines down to the relays. That shows you the stock relays.

[Trimpe.bob@gmail.com]

I found a great thread buried in the archives. It’s title is “Wiring Path for Electric Fuel Pump”. I also copied the graphic from the thread identifying the relays on the kick panel. It may help the next guy find it without help.

Appreciate the fine advice from Steve. I need to spend some time rummaging in the archives!
 

regards,

Bob t

[SteveJ]

Thank you for taking the time to wrap up the thread, and welcome to ClassicZCars.

[Blitzed]

Hi All, 

Hope all is well. Have a few relay related questions. 1973 240Z late production. 

First - My passenger side kick panel relay pic is below. Based on the diagrams in this post, the bottom relay is the Air Conditioner relay. I've removed the AC from the car and all switches. What would cause this idle relay to warm up when the engine is running?

Second - Would any of the other three relay create noise? tracking down noise near my ECU, pausing. 

Third - I disconnected the relay on my firewall next to my grounding plate. I can't locate any info on this relay on this site. I found an article on a relay's on later Z's with Hitachi carbs that used a decel type of relay??? Not sure. But when disconnected had zero effect on the car. 

 

 

[dutchzcarguy]

11 hours ago, Blitzed said:

near my ECU,

You have a very special 240z.. A ECU ???  please go to "home" and then to +create (right top..)  and create your own topic about your problems! 

Your car must be modified then.. a 240z has no ECU...

[Blitzed]

Hi Dutch,

Yes, in the process of converting an NA L28 to a modern EFI system and the old girl is fighting me. No the car is not very special yet :). 

As many have previously done, adding a ECU (Haltech) and trying to not disrupted the existing harness as much as possible. Only four connection points to the old harness, tach, coil (delete wires), ignition wire and fuel pump. 

Engine starts, runs with the above wiring completed. What I'm fighting is component or components (relays, terminal) creating RFI noise, not good for the ECU connection.

The Haltech CAN display in the dash stops working at start up. Could explain this a potential drop in voltage causing the problem, not sure yet. 

The ECU has a different issue will stay connected for various lengths of time but will discount from the PC (engine will continue ti run). Thinking this disconnect could be terminal related as the car warms up, maybe a terminal switch or relay gone bad????

It's a process of elimination. 

[Blitzed]

Sorry, meant thermal related, spell check ;  )

[Zed Head]

Trimpe.bob is still around and you've kind of hijacked his thread.

I was going to suggest that you put the details of your car in your signature but something has happened to the site settings and that option is gone.  A person used to be able to Edit their profile but the Signature option is missing now.  @Mike

Study ground loops.  Sometimes you just have to add and disconnect grounds randomly to get rid of them.

https://en.wikipedia.org/wiki/Ground_loop_(electricity)

[Blitzed]

Hi Zed,

Will go through the bylaws on the site. Previously members suggested, search the site, info is here. Was not aware once you found the specific info responding to the thread was not an option? With a new thread started on each search of the site, the redundancy could be overwhelming. 

Thanks for the info on grounding. All ECU grounds are star grounded to the head.