OK, my brain is fried. Wiring diagrams are just a blur to me now.

I'm trying to find out where these wires go but I can't track down the MS3 wiring diagram that was provided for the previous owner by Brainiack.

Trying to track down where all these ground/red wires go and why a couple of them are unconnected.

I'll try to explain clearly with each picture the problem at hand.

This is the MS3 connector. The Blue/White coming out of the connector has a Black(lets call it a ground) wire poking through the butt connector; connected to it and then it ends. Can't find the MS3 diagram to find out where it should terminate. Also all the thin gauge wires were not connected at any point so I don't believe they are an issue.



Travelling farther down the previous connector comes to a junction with a black "ground" wire coming out of the cable. The only issue is, is that it is connected to one of the thin gauge wires that were not connected(GREY). So I'm unsure if it was ever connected or not. Again, all the thin gauge wires were wrapped in electrical tape and unused.



Connected to the thin gauge PINK and RED wires are a thicker gauge black and red wire that are unconnected.



I believe this is the wideband LC-1? Unsure what this even is(I'd look it up but again, my brain is fried).
Black ground wire exiting it.



Shiny spangly cable with two connectors coming out of it. I believe it plugs into the main MS3 Board.



Any help with those who know MS3 would be greatly greatly appreciated.

 

Maybe PM Braineack a link to this thread!? I'm almost positive he will be able to give you an answer to most if not all of these questions

 

Thanks BT!

 

No problem hopefully he can get you pointed in the right direction!

I'm completely lost because my brain-built ms3x looks like this...

 

what in the world am i looking at?

 

+1 what Brain said, I wouldn't even try to use this mess of wiring.

I think (in compliance with your faible for detail you show in your build) that you should tell Brain or Reverant what kind of setup you have (WB, MS variant, etc. And get a new harness made...

Greets

 

Thats definitely going to be the best way to go

 

I'm inclined to agree at this point. No offense to Dave, the previous owner, but this is the most hacked up wiring in a car I've seen.

 

I wouldn't even trust this mess to light a single LED bulb properly, I would never ever install this in a car...

 

Ok I decided to spend the time to tape it down and take some "big picture" photos to get the wiring path more easily able to grasp.

Here is the engine management as per the previous owner:
Engine Management:
Professionally built Megasquirt MS3x
Dual MAP sensors
Sequential fuel
Sequential spark
Knock module
Closed loop idle control
Closed loop boost control
Fan control
AEM WBo2 sensor
99 intake with active VICS
m-tuned dual feed fuel rail
750cc RC injectors
Adjustable intake cam gear
Toyota coil on plug conversion
Resistorless race plugs
Knock sensor

Sorry my camera died before I could take more.

To the left you have the dashboard harness(connected to the dashboard, not the huge wire harness).
At the top is the boost gauge and MS3X main board that the connector in question connects too. It looks like the cable is for spark and injector control.
Top right is the COP
Bottom Right is the EBC
Bottom Middle Is the AFR/Wideband















Hopefully this helps you a little more.

 

W

 

T

 

F

 

My sentiments exactly.

 

So Brain I know you probably don't even know where to begin but in a manner of how do I solve this issue I have no idea.

Wiring unfortunately is my weak point in cars, especially Miata since I still am not too familiar with what every plug/connector/wire does. AND, it doesn't help that the wiring harness all through out the car is fairly modified from the beginning.

Do I:
Get a new COP Harness
Replace the in question mystery MS3 connector
all the above?

Do I connect the red and brown wires coming off the mystery cable and hope for the best once I get the car all together and address non-start/errors with the car assembled?

I just don't know where to go from here since this is restricting me from putting the dashboard in and interior and progressing the car further.

I wish it was me that caused these headaches but there were a lot of wiring issues before the car was disassembled, so I am not sure what was caused by stripping the wiring harness out of the car and what was already an issue before the car itself was disassembled.

 

Did you pick the previous owners brain about it? Maybe he will remember?

 

Also I can remove more wire shielding if it helps determine wire paths more accurately.

 

I did, he can't remember.

 

Pinouts:
Megasquirt-3 MS3 Hardware Manual
90-97 MS3 | Frank's Westfield MX5 90-97 MS3 |

 

Thanks Vitamin, I'll take a look at these tomorrow.