mtx-l install help
 

Busy installing my new mtx-l and ms2 from reverant. Got the ground wire and sensor cable routed from the engine bay and now doing the sensor wiring. I would just like to check with guys who are a whole lot more competent than I am with this :facepalm:

Looking at the harness on my car right by the ECU, the red-blue wire (for the stock o2 sensor) is connected to a thick black wire, not sure why but should I just connect the yellow output of the gauge to the red-blue wire and forget about the black there? The o2 wire is still red-blue in the engine bay.

https://www.miataturbo.net/attachmen...ine=1326101244

Also where can I find a source in the car close to the radio for the white wire (dimming function)

Sorry for the stupid questions, I'm useless...

Didnt reverant provide pins for you to wire the MTX-L directly to the db15?

specifically pins 1-4? Where you could have run power, ground and the input right into it?




Behind the radio the Red/Blk is the proper 12v wire for the dimmer.


Looks like that R/L wire on the ECU harness is just shielded.

I hadn't planned on the wideband right away so I never requested the wiring for it with the ECU. Maybe I should have but that's fine I guess. I have power, dim and ground so it's just the input I'm not sure of now. Would wiring it into the stock o2 wire be right?

yeah, just make sure you remove the stock o2.

Perfect, will try finish it up later

Nope. His MS2 is an MS2V3, not a DIYPNP.

It has been a while, didn't I sent you a 12-pin connector that has a bunch of free wires on it? Does it have a yellow wire on it? If so, that is where you are supposed to connect the wideband output.

The wideband took ages to ship from america (good price though), so it has been awhile. Nope no 12-pin connector, I think the only changes you made on it was the different wiring for the sequential injection (I'm not going to change to that yet). Where must I connect up the wideband output then?

Open the DB-37 connector. There is a yellow wire on pin 23 of the connector, that goes to 3F on the blue connector board. This is where you need to connect the wideband.

There is a grey wire running from pin 23 to 3F, would this still be the one to connect to?


https://www.miataturbo.net/attachmen...ine=1326181651

Also the second grey wire used from the DB-37 (pin 27) has come off the blue connector board. which input is that from? seems to be from between 1A to 1V.

Yes, that is the one. I used to use grey as the wideband wire, now I use yellow to match with the LC-1 color-coding.

Pin 27 goes to 1Q.

Thanks so much, I will try sort it out and get it running today.

Awesome, the wideband is working and the car is fine, its reading about 0.2 higher on Tunerstudio than on the gauge. Got an odd problem though...the aircon won't turn off now! :vash: haha any ideas as to whats going on there?

There are two "1Q" holes in the blue connector board. Is there any wire attached to the other 1Q hole?

There is a blue wire connected to the 1Q on the top middle of the board and the grey wire I reconnected to the 1Q on the bottom right of the board

If you follow the blue wire, does it go to my expansion board?

Correct it does, it never did this the last couple times I connected the ECU to the car though.

Contact me through email to track it down faster.

done

The "thick black wire" is actually a shield, which surrounds the red/blue wire but does not connect to it electrically. Essentially, it's just a braid which completely surrounds the red/blue wire, and then has some black insulation around it. The braid is grounded, and it's simply there to reduce the amount of noise which the red/blue wire picks up from the surrounding wires. Functionally, it's similar to coaxial cable.

That makes sense now :) And the aircon is all sorted now, Dimitris is a genius!! :bowdown: