I知 trying to wire up a new head unit in my Chevy Express and I知 confused about this. Red/White is supposed to be accessory, orange is supposed to be dimmer/illumination, and the black/white is ground. The rest are speaker wires. So where is the yellow constant power wire? Thanks in advance

 

It would help to know what year van it is.

My 2011 didn't have a wire to signal the head unit that the lights were on. I hooked up a toggle switch to dim the touchscreen I installed last year.

If you just need the constant + you can tap into the fuse panel or some other power line behind the dash.