Innovate LC-2 installation in progress - wiring guidance requested
 

Greetings. I am in the process of wiring in an LC-2, along with Innovate's G-5 analog gauge. Right now I am focused on the wideband controller. I've got the sensor in the exhaust pipe, and the cable into the cabin via the rubber shifter boot. I am planning to mount the controller somewhere not too far from the stock ECU. I am not what you might call an expert when it comes to electronics. Far from it.

The LC-2 appears to be different with respect to the wiring than the LC-1. For my purposes at present, I need at the very least (i) switched power (and probaby not associated with the ignition system) (ii) ground, and (iii) one of the analog wires to the G5 gauge. (The gauge itself will need a little more.)

I am planning on putting in a standalone ECU in the future, so I would rather wire this thing up now in such a way that it will work correctly when that day comes. From posts I've read, it looks like I need to use the same ground for the standalone ECU and the wideband controller. I am considering putting in a wire grounded to the engine block or perhaps to the engine block's ground strap, and running it through the fire wall to serve as a dedicated ground source. Is this necessary, does it make sense, and if so, what gauge wire should I use?

The Innovate instructions suggest using a relay. I happen to have a relay lying around that I could use. The schematic diagram in the Innovate instructions contemplate a constant power source from the battery into the relay. Should I run a wire from the battery, or is there another good source for constant power for this purpose? If it is to come from the battery itself, where is the best path for routing the wire? Again, what gauge wire should I use for this line?

It looks like the wires from the controller for power, ground, and the analogue output are about 20 gauge wire. To the extent I need to extend any of these wires, would it be inappropriate to use 18 or 16 gauge wire to extend them, or should I keep searching for the same gauge wire?

Edit: It's a 2000 base.

Thanks in advance.

Hey, looks like you are on the right track but it seems that the instructions for the LC-1 apply. You should search this site, lots of detailed write-ups with pictures. It should be a better resource than getting non-specific answers.

Also check the Megasquirt section for wideband grounding/offset.

Thanks. I'm now inclined to use the window switch for power, and ground it where the ECU box bracket is bolted to the firewall, and re-address it if necessary when I make the leap to standalone.

I personally found the perfect location for my lc1 is right in front of the shifter and i route the wire right under the boot.

In the first pic you can see where hte cable goes under the boot to the left of the shifter. I know its hard to see because of the other cable blocking it.

I know you're installing an LC2 however from what i'm told its about the same size/shape.

https://www.miataturbo.net/attachmen...ine=1393648382

https://www.miataturbo.net/attachmen...ine=1393648382

The LC-2 has about 40 inches of cable between the O2 plug and the controller itself, unlike the LC-1. I have the connection between the O2 sensor and the cable (which is itself about as big as the controller) lying where your LC-1 controller is located in your first photo.

I mounted my controller in the metal framing under the dash, where I can get to it - and view its red/green status light - if I remove the dash panel under the steering wheel.

I used the window switch power and located the unit under the shifter console.