740 console wiring ques

Just installing a boost gauge and am taping into the console lighting, wondering if the blue or the white wires are 12v? I would just hookup my batt and figure it out with my voltmeter but my wiring is out of commis right now.

So yeah, the lights have white and blue wiring to them. One I was gonna take power from has two white wires coming to it.

Also sidenote. I was gonna hookup this narrowband a/f gauge I had sitting around but decides not too at the last second. I don't have installation instructions with it. But it has a tach connection as well as an o2 connection. That normal for narrowband? Wondering for future reference

Anyone.. Anyone? My guess is the blue wire..

Technically, you'd use both. The white wire gets 12v from fuse 21, the blue provides a variable ground signal via the dash dimmer knob, under the temp gauge. White and ground would give you full brightness all the time.