Location to tap a switched 12v line near rear view mirror

Location to tap a switched 12v line near rear view mirror

I run a Valentine 1 radar detector. i like it mounted just to the left of my rear view mirror. On my previous BMWs I could find a switched 12v wire related to the dome/reading lights I could "tap-a-line" into for a hard wired connection to the plug.
The tech at the SC thought I should run a wire all the way from the rear view mirror to the 12v courtesy plug in the console.
Any suggestions for the closest switched 12v line to the rear view mirror?

PBEndo | 2013年12月15日

There is a switched 12v in the mirror housing.

PBEndo | 2013年12月15日
bradtesla | 2013年12月15日

Hi Bryan, I'm going to use the Valentine One SAVVY and thread the wire up through to that area. There's a few benefits to the SAVVY that make this a good way to wire it. (Hope to have it done in the next few days.)

togliat | 2013年12月15日

Please post your results I would be very interested. I have a valentine one. My understanding is that a detector gets best reception being mounted very close to the glass and preferably to the right of the rearview mirror where there is no metal film blocking much of the signal.

Time for me to re-read pbendo's link above!


bradtesla | 2013年12月22日

Update: the SAVVY does not work. Going to have to return it. Also, I must have a newer Model S that's missing the 12V tap near the microphones.

skulleyb | 2013年12月22日

This one will show you where the 12v is located:

nickjhowe | 2013年12月22日

@pbendo - are you sure there's a switched 12V in the mirror housing? I thought it was unswitched.

ajmail01 | 2013年12月22日

I did a self install of the 9500CI and placed the display module and LED in the mirror. All the other components were installed like the other members did.

I popped the left side of the mirror base (where the rain sensor is) and then twisted the mirror column to the left and it came right off. It is held on by a plastic tie wrap that I cut and then disconnected the cable.

Once the mirror is off, the slow part is prying the plastic case from the glass and circut board. I used a flat jewelers screw driver and thin spudge to slowly work around the plastic border to finally pop the front of the mirror from the case. The secret is to pry the case up and then use the spudger to GENTLY move the mirror forward out of the case. After a couple of times around the perimeter the mirror/board will come out.

The circuit board is attached to the mirror with 3M tape, but has a rectangle area on the right that almost fits the width of the display module. I dremeled the plastic around the opening and then removed the tape to make the module fit. I should have made the opening slightly wider to account for parallax from the left seat ( the left half of the first letter pixels are slightly blocked by the tape - should have moved the module more to the right).

The modular connector at the end of the wire from both the Module and LED need to be cut to thread the cables into the mirror column hole where the circuit board cable goes. From there it's easy to run the wire under the liner to the A pillar. There you unscrew the Torx screw and run the wire down toward the left door jam. But, the problem is the wire is not long enough. I called Escort and they said to use telephone wire and a modular telephone inline connector to finish the run. For some reason (voltage drop??) this did not work and I ended up soldering both wires to complete the connection (even though Escort says not to do this, but it works fine for me). By the way, the modular RJ22 connector is a SMALLER that the standard RJ11 Telephone connector. I could only buy the RJ22 online and they are not sold at Radio Shack, Lowes or Home Depot, but can find them here:

The LED bulb fits perfectly into an existing hole on the left side of the circuit board (almost like it's made for it). I just used electrical tape to fix it in place and then ran the cable with the display module one. Of course you have to remove the tape where the bulb contacts the mirror.

Hope this info and pics help and you can email me at for more info.



Big T | 2013年12月22日

Wow AJ, awesome info and pictures. Thanks! I was thinking I'd have to ship my mirror to these guys in the Dallas area. Saves me $500.

ajmail01 | 2013年12月23日

Thanks, only hard part is getting the mirror/circuit board out of the plastic shell. Just take it slow and easy and work around the perimeter several times and it will eventually pop out. When done, it's easy to pop it back in.


PBEndo | 2014年1月4日


Yes there is switched 12V in the harness going to the mirror.

PBEndo | 2015年1月25日

I had my mirror housing off the other day while installing a new dashcam. I remembered the question about the switched power and took a pic of the wiring harness in the mirror base.

I hope you weren't waiting all this time ;)

PBEndo | 2015年1月25日
PBEndo | 2015年1月25日
PBEndo | 2015年1月25日
Brian H | 2015年1月25日
tigerbuny | 2015年1月25日

52 processors running off the 12v in the vehicle. Chronic problems with the 12v battery. And you want to connect your radar detector to that same system!? I hope you plan to replace the 12v battery every 6 months instead of the normal 12 month cycle.

PBEndo | 2015年1月25日

I have never had a problem with my 12V battery, (currently nearing 39,000 miles) though my main battery pack was replaced due to a contactor problem.
Your concerns with the radar detector would apply to any 12V accessory since the 12V system powers the lighter plug and the USB ports (at 5V). Better not plug anything in!

martinwinlow | 2015年3月28日


Just to be clear:- of the 3 wires shown in the last 2 photos, which is the switched 12V? Red = +ve 12V and black = 0V? If so, what does the yellow wire do? Regards, MW

PBEndo | 2015年3月28日

Sorry but I did that install 2 years ago so my memory has faded. I think the black was constant -12V and the red was switched +12v, but I don't know for sure. In addition, there have been several changes to the hardware since then so YMMV.