[jakedog]

2021 M550i, I plugged red into red and black into brown, yet my radar does not turn on when I plug it in. Am I supposed to be plugging into the magenta wire harness or only the black one? I shined a flashlight at my mirror to confirm it has auto dimming function.

Thanks

[Brainbot1]

Hello, did you end up figuring this out? I would connect to a 12V battery to verify the cable works. If so, then connect a multimeter to your pins when the car is on and verify power and ground that way. If that is fine, then verify you have good contact points.

[Sam_M550i]

Anytime you doing anything like this you need a multimeter set to DC to measure what wires have 12Vdc. It's not a guessing game. Double check which wire has power.

[Baap540]

Had the same issue and I couldn't figure it out. Bought new mirror taps and it still didn't work.

So I bought a hardwire kit off Amazon:

Uniden RDA-HDWKT Radar Detector Smart Hardwire Kit with Mute Button, LED Alert and Power LED, for Uniden R8, R7, R4, R3, R1, DFR9, DFR9BLK, DFR8, DFR7 and DFR6. https://a.co/d/68UJJ8x

I followed the guide below:

https://www.eyephysics.com/BMWG30/bmwg30.html

I ran the wires to the left instead of up the pillar. Tucked the wire in the gap above the the cup holder cover. Mounted the mute button with double sided velcro (which came in the kit) to the side of the center console and then ran the rest of the wire under the steering column panel, up the left airbag pillar and into the headliner next to the rear view mirror. Took about 15 to 20 Mins for a clean install.

If you need more pictures of how I ran the wires, just let me know.

The radar has been on for about 5 days and can confirm it auto shuts off after 5 or so Mins.