Currently planning out my wiring harness and needed some help understanding more about how the stock dash works. I want to make a custom wiring harness for all the new sensors and EFI system, I'm putting into my fd3s. Can someone please explain to me how I'm able to keep all the dash functions such as fuel levels, low coolant, oil pressure, essentially I want to keep all the functions of the stock dash while adding new AEM gauges and a custom wiring harness for all the new sensors. Can anyone give me suggestions on how to do this? I'm trying to get a better understanding of how this would work.

My assumption is that there are 2 separate wiring harnesses within the vehicle. one that connects directly to the dash and then the main wiring harness which would be for the sensors and efi system that connected into the Haltech elite 2500 via the 34 and 26 pin connectors. but I'm kinda lost from here on how I would integrate keeping that stock dash working with the elite 2500. Would I need an expander box? I tried using the google thread search on the website but had trouble finding an exact answer. Any guidance would be very helpful thank you!

 

Rywire makes a patch harness for exactly this, it will save you a ton of time

 

I have a '94 wiring manual pdf that would give you the requisite information to accomplish what you are trying to do. It's too big for me to attach to this post and I don't recall the link I got it from, but I can email it to you if you would like.

 

I'll take it too please!!!

My email: mazda_rx7_1993@icloud.com

Thank's

 

Managed to create a link to a google drive that has the manual. It can be found here. https://drive.google.com/file/d/1x2g...ew?usp=sharing

 

I would also speak with Chris Ludwig as a secondary option. LMS EFI is the name of his company and he can make a custom harness to your specification. https://lms-efi-llc.myshopify.com/

@C. Ludwig

 

@iceman4357 Yeah I’ve been in contact with LMS- EFI. I’m trying to do research to find what tools/connectors I would need to design my own harness. Just a skill I would like to invest in. Any additional resources would be helpful. Thank you!

 

@spintowinrx7 Check out the "Motorsport Wiring Alliance" group on Facebook. There is a ton of good information regarding techniques and theory of wiring and there are a lot of hobbyists and motorsport wiring professionals in the group who are able to give good insight as to why things are the way they are. If you do some searching there you will be able to see what kinds of tools people are using, how they design and manage their harnesses, and other very helpful and insightful information.

I'm in the design stages of redoing the chassis harness on my car because I have a habit of fixing things that aren't broken until they are very much broken and will be redoing the front ring, rear, dash, and door harnesses, as there are a ton of connectors and circuits that won't need to be there after I am done with it.

The planning stages of this kind of work are probably the most intensive. If you go through the trouble of planning and documenting every single aspect of your harness out, there should be far fewer unpleasant surprises down the road that would require you to start over.

 

Brave soul. I wish I had the patience and time to do so myself. Kids and responsibilities take up time.

 

@SETaylor This is exactly what I’ve been looking for!! Thank you!! Just joined the group. I have a basic understanding after watching videos and reading some forum posts. But there are still gaps in my understanding that I would really like to understand. Currently in the process of ordering the last parts for the engine build and then its time to send the engine out to chips motorsports for engine work. Once I get it back and assemble it the biggest challenger is going to be the wiring. Im pretty confident in doing the startup tune myself but im stuck on this wiring part so hopefully that FB group can throw a lot of info at me.

 

@iceman4357 I guess being 23 with no kids or responsibilities is a perk LOL. I pretty much work on my cars and I’m usually reading books or studying about cars when I’m free. I think I have the patience to learn this skill. Wish me luck!