Wires for the power port are behind the pass side carpet panel . Wh/blk heading to the power port side of plug is 12v . If you want to make sure you have the right wires unplug the 2 pin connector and you will see the socket goes dead ! Easy peasy lemon squeezy !
The power connection I show in my pics is the 12v cig socket not usb . The grey 2 pin connector is stuffed under the center console by the usb connectors , pull the harness out and you will see the 2 pin connector in the photo . This IS the socket .
I just did this in my refresh March 2017 S90D and found a slightly different configuration in this location. I figured I'd post some pictures in case anyone else was looking for a 12V source in the passenger foot well / glove compartment. You need to pull most of the side panel of the center console off ( careful with the rear, the vents snap into this piece and need to come out first), I was never able to remove the center console passenger side piece (not enough leverage), but got it off enough to pull the carpet piece under the glove box out. Here is the back of that carpet panel And behind it you will find the USB connectors (they were labelled such in my car, something like USB to MCU or something), tucked back into the center console is a connector that you can unplug by pushing down on the top of the white tab and pulling out, this is where my cigarette lighter and rear usb ports seem to get their power from. I just picked a red wire and black wire on the outside, attached a multimeter, locked / unlocked doors and watched power go off and on. Matt
Just wanna say thanks for this. I already had my refresh ms to this point with the carpet pad removed and visible USB cables. I saw the loom and pulled the wires out but didn't want to start poking them to test. I knew the cig socket was switched but didn't know there was a plug just a bit further in till I read your post. Found the plug. Successfully tested both thick red wires to get a good switched 12v source. T tapped the wire closer to floor, added a fuse in line and my wire and perfect!!
One wire is for the 12V socket (15A), the other one feeds the 12 to 5 V transformer which feeds the 2nd row USB ports. BTW: the USB connectors allow an easy upgrade to move one USB data port to the glove box where you can safely tuck a USB or SSD disk to record sentry on and play music from. I took one USB cable from the center console and fed it to the glove box. Then sacrificed one USB port from the back and fed it to the front port (power only, no data). Using an old cable laying about I could replace the 2nd row USB, but without the LED inside.