Thanks, I'll check that out as soon as I get back on Tues.

Appreciate the input.

 

I found the oem ecu ground location.

It is in the engine bay @ ground point #3 (Miata Fac. Wiring Diagram book page Z-21) on the forward right side.

Guess I'll put the ground there.

 

I think the 12v on the power window connect is one of the black ones with a white stripe.

I have power windows and have 2 gauges hooked up to that 12v along with my wideband. No blown fuses even while rolling down both windows at the same time (to test)

The other white plug is just the power connector for the ashtray bulb in the center console. It's pretty useless

 

This was operator error... cheapie volt ohm meter...

The BW wire is powered.....

I'm on my way.

 

I'm hooking power/ground for my WBO2 at the ECU, so my question isn't specifically about that. However I'm also installing two other gauges at the same location (above the radio) and am wondering about how to provide power for their lights.

Right now my thought is to snip off the ashtry light connector and use butt connectors at the red/blk (+) and red (-) wires for one gauge, then tap into the power window harness for the other gauge light with a spade. I understand that the black/white wire is +, but how did those of you using this harness do the ground? Is one of the wires a ground or did you go to the chassis? These are just lights for boost and oil temp gauges so there's no big load.