Im installing a wideband and requires the WHITE wire to connect to a Headlight Wire. Anyone know of the color of the Headlight wire by any chance?

 

https://www.evolutionm.net/forums/ev...ll-w-pics.html

This thread says you can use the green/white wire located at the dimmer switch if you want on/off without dimmer.

Further down it somebody mentions that you can use the yellow/black wire at the dimmer switch if you want to be able to dim your gauge..

 

Just came across this during a search. For future reference: DO NOT use a dimmer wire power source for an electronic gauge (wideband/e85/other electronic gauge) operation. It needs full voltage to operate correctly. Electronic gauges detect power to from the headlight switch so they know to dim.
The potentiometer of the DIMMER switch is wrong for powering electronic gauges. It is ONLY okay to use for the light bulb in a gauge (mechanical boost/oil/water/etc) so that it dims with the gauge cluster.