Can verify that the red wire on the right side of the passenger footwell works as a switched 12v on the 2023 Model Y Performance. I wasn't sure if the trailer brake controller method on the driver's side would work on mine since I don't have the tow package, so I went with this method. In retrospect, I would have ordered the adapter and tried that first since it looked easier.
There are A LOT of red wires (not just 3). I counted 9 thin ones ranging from red to blood orange to slightly fuchsia, 1 thin red wrapped in thin blue, 1 thin red wrapped in thin white, 1 thick red wire (THIS is the one you want), 1 thick red wire wrapped in thick blue wire, 1 really thick red wire shown off to the left. The correct one was buried pretty deep in the bundle and took a decent amount of tape-cutting to access.
I thought finding the correct wire would have been the toughest part, but I had trouble tapping into the wire with the t-tap connector that came with the Uniden radar detector wire kit I had ordered (
link). The blue connector it came with would have been fine for the thinner wires in the bundle, but probably needed a slightly larger awg wiretapper for the middle-size wire I tapped into.
The last part I would have liked to avoid was grounding the other wire. There weren't any bolts on the frame within reach so I had to drill a new hole. Went through two drill bits that weren't sharp enough, and a self-tapping sheet metal screw failed to penetrate as well. Finally got it drilled, but a bad ground connection here made me waste a lot of time because I thought the hot wire was the issue.
Got it working at the end though. Thanks to everyone else who'd already tried it and posted their pictures.
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