I need to know how a wiring harness is routed on a 96 Miata. My 94 runs behind the seat, and from what i've read so does the 96.

If my research is correct, i need to know if there is a second "loom" if you will that runs along the floor board behind the seat(From ECU) that plugs into the wiring harness? I suppose i could go rip apart my car and figure out, but you guys are smart.

I got a wiring harness in the mail, and it has no where to plug in the ECU. So i was originally confused if i didn't get all the harness, or what's wrong.

 

Just FYI the 96 and the 94 wiring harness are completely different. So if for some reason you are trying to mix and match the 94 and 96 harness you will have tons of problems.

 

No no. Not at all. I want to try and use a 96 harness to run a BP in another car with a 96 ecu.

 

No one?

 

IIRC it runs all the way back to the ECU, there's no "patch" harness if you will...

 

So if a 96 harness runs all the way back, this one certainly does not.

In this view, it would be as if it were in the car. Diagnostic box over on the left, and the majority of connectors on the right side. But the bottom left where it T's off looks like where the ECU hooks up. Clearly not a harness from a 96. Man i hope i didn't get dicked hard with this one...




Obviously, neither of my ECU's work.



Edit* This was the FS thread. https://www.miataturbo.net/miata-par...ts-list-68666/

 

Any insight?

 

I've been through most of the wiring in my '97.

The top ECU in your pic looks like a 96 or 97 ECU. On a 96/96 The engine harness comes through the firewall on the passenger side, and plugs into the ECU harness under the dash which runs across the floor and behind the passenger seat.

There is a smaller harness that comes through the drivers side, but it just handles the diagnostic connector and things like turn signals, horn, etc.

Edit: either I'm missing something, but I don't see the part of the harness that runs across the floor.

 

This one had 2 rubber grommets on it. One grey on the left in the picture, and one black on the right.

What year is this harness? I clearly don't have what i think / told i have.

 

Shameless self bump.

 

I circled the part where you should have a section going back to the ecu. There is a 96 at my local pick and pull I believe. I may be able to get up there later this week and grab that section that goes back to the ecu and ecu also if you want me to.

 

I will forever be in debt to you if you were to do that.

 

Shoot me a pm.


This is roughly what the section looks like that you are missing. I can tell you that this section is different between 94-95-96 and that none are compatible. You are also missing the part that actually goes in the dash I believe.

 

For all Miatas, the wiring harness comes in several different sections, which join together at the "common connectors" indicated by the X's in the wiring diagrams.

What you have there is a Front Harness.

 

I see. Looks like my connection is this:



The part that goes under the dash controls everything, cluster HVAC OBDII port, ect.? The body and engine harness on these cars are all in one from what i'm understanding. So i'll be not using a lot of plugs. Edit* i'm not even sure ill need the under dash harness, or any other parts of it.

 

The naming conventions are kind of weird. On the 1.6 cars, for instance, the "Engine" harness actually has very little to do with the engine, but it does go all the way back to the battery, and also includes the main (under-hood) fuse box. The "Front" harness, meanwhile, contains most of the engine electrics including the ECU connectors. (ECU is under passenger's feet in these cars.)

I wish I had a copy of the FSM wiring diagrams for the later NAs, but unfortunately I have never been able to find a complete one- just the sections specifically pertaining to the ECU, and without the overall harness illustrations.