DIY: Hardwire Radar Detector
 

Dear All,
I searched around on the forum for a while and found no clear, clean and definite answer to my question of: "which wires do I tap into, when using the overhead controls, to hardwire my radar detector?". Well, I decided that I would tell everyone so people have a clear answer in the future. One of my struggles came from my problem with locating a suitable ground for the radar detector, as a previous post suggested that one should attach the ground wire of the radar to the mirror fastener screw. Well, on my 2012 coupe, I could not locate a mirror fastener screw to ground the radar to. Thus, as detailed next, I tapped into two wires directly, rather than using the car body as the ground point as one would normally do.

1. First, using the special tool that is provided when one is granted a new credit card, $tarbucks card (as previously suggested in another thread), or condo laundry card (as used here), push upwards from the middle of the overhead controls until the whole thing drops down. You can use a decent amount of pressure before it will pop down. You'll be fine, just keep pushin'. Once it pops down, do not attempt to pull this control center all the way down. Once it drops, you can manipulate it downward another inch, but if you keep pulling down, I believe something serious would break. It will fight you, so be reasonable when trying to work your hands in this space when threading wires.

2. Once the unit drops down, I found it best to thread all of my wire (my radar of choice grants an unnecessary 8 feet of wire, when you really only need 1.5 feet to get the job done). Thread the wire through the passenger side of the headliner. My headliner was very tight, so I had to thread it through the middle part of the passenger side which permitted the most amount of bend without fear of breaking anything, and then slide the wire back toward the mirror when I was finished.

I also had a lot of difficulty threading the wire from the rear-end of the car toward the windshield so I changed my approach. My recommendation is to thread some wire from the windshield toward the center roof controls, and once you get your hands on the wire, tie the proper end to that wire and then pull the everything backwards. Its almost like using gentle coat hanger to pull the wires back through the headliner (I wouldn't recommend a coat hanger as it will potentially scratch the windshield, pierce wire or damage something). Another way to describe it is like threading a string toward the roof controls and tying a knot around your radar wire and pulling it back through where the headliner meets the windshield.

3: In my 2012 coupe, the wire bundle was numbered "A 207 5400009," however your's may be different. See second attachment. Another user posted his, and the numbers were different. We both used the same bundle though, so use the one pointed to in the third attachment with the black arrow.

4: Attaching your "Hot" wire. Tap into the red wire with a black line. Unfortunately there are two of these same colored wires in the bundle. The correct wire is the red wire attached to the connector via the rear-most electrode/hole of that connector. See attachment 4.

5: Attaching your ground wire. Tap into the brown wire. Unfortunately there are multiple brown wires in the bundle. The correct wire is the brown wire attached to the blue connector via the front-most, and top most electrode/hole of that connector. See attachment 5.

6. When you're finished tapping wires, bundle everything back up, push the wires out of the way (I pushed them toward the passenger-side headliner where there is extra space) and then push the roof controls back upwards until it pops back into place.

Test the radar unit by locking an unlocking the vehicle. The wires I used are switched and are connected to the map lights. The radar should turn off after around 10 seconds after you lock your car. Unlock it, and the radar should power back on.


I AM NOT RESPONSIBLE FOR YOUR ERRORS WHEN INSTALLING YOUR OWN RADAR USING THESE RECOMMENDATIONS. IN FACT, THE FOREGOING ARE JUST THAT; RECOMMENDATIONS. USE YOUR OWN MULTIMETER AND CHECK THE VOLTS OF THOSE WIRES BEFORE TAPPING INTO THEM. GOOD LUCK. ALL WARRANTIES IMPLIED OR EXPRESS ARE WAIVED AND INVALID. DO NOT COMPLAIN TO ME IF YOU FAIL AND/OR BREAK ANYTHING ON YOUR CAR. AS NOTED, THE FOREGOING WAS CONDUCTED ON A 2012 C63 AMG Coupe W/ P31, USA SPEC.

I would not recommend tapping wires. Eventually the wire will get cut in half. Plus it's not easily reversible. It would be much better, easier and safer to tap a fuse in the trunk using an add a circuit fuse tap that you get from a local auto parts store. That's what I have done on all my cars. Trust me, losing power to your radar detector on a long road trip because the wire tap slided the wire in half sucks...it's basically a knife used to touch the metal core of the wire.

Fair. A sliced wire has never happened to me before using this method, and I have always tapped wires. I just wanted to give new members some good info on wires to tap if they so choose to use this method. Obviously, as you have noted, there are alternatives.

^^^absolutely, man! It's always good to have the info out there. Thanks for taking the time to put all that together.

In the thread you speak of that I had some instructions and pics, I used these wire clamps that V1 sent. You just squeeze them over the desired wire and it pierces through the cover and does not damage the wire. I'm sure you can obtain these from radioshack but v1 has them on their site.

Exactly. They are called wire taps. You can buy them almost anywhere and in different gauges/sizes.

Thanks for the write-up, couple questions:


If you don't lock your car is it always "hot" (I never lock my car in my garage)


What type of wire did you use, the flat phone wire?


I am probably going to wire up a Redline (Virginia)


Just need a bracket to mount it - up high

The wire I tapped into is part of the interior lighting system, so it will turn off after about 5-10 minutes once the car turns off the electronics.

My radar is not a V1 or a redline, and it uses a simple black and red DC power cable with a male round DC style tip.

good stuff. thanks, OP, for figuring it out and posting.

also, for anyone that cares, the V1 wire used for hardwiring is a standard red/black deal, not the Ethernet-style cable.

Just followed this DIY to install my V1 in my 2012 C63 coupe. so far so good.

for the ground, I used a screw driver as a shim to hold open space between the body of the car and the mounting hardware for the mirror. I shoved the ground bracket in there, and then removed the screw driver so it was wedged in. So far no problems with that, was easier than running to the store to get a second tap kit for the ground wire. I prefer my V1 mounted at the bottom drivers side of the windshield, so I ran the cable from under the console light, tucked under the headliner above the drivers sunvisor, then down the A pillar tucked behind the airbag. Then i ran the wire under the drivers side of the dash so that the connector appears behind the instrument cluster near where the VIN label is. very clean.

So far, I have not seen the switched functionality of the black/red wire tapped, but perhaps I have not let the car sit long enough. For now I have been using the switch on the V1 itself to cut power. Overall, the most helpful DIY i found on this website, thank you!

Glad I could help. I was just trying to give back to a community which always helps me immensely.

how one go about finding electrical diagrams? only had bmw before and used realoem.com which is awesome and gives all electric and parts diagrams.

I have a x204 2012 glk and was wondering if the dome lights wires are the exact same as shown here. if not how do I make sure I'm getting the right one?

did you use the wires for what exactly? map reading light switch? I don't think none of my lights go off after I lock the car :( ...was thinking of tapping on the sunroof switch

Gcbmb: fwiw I plugged into the cig lighter outlet in the glove box and ran the wire up the A pillar and headliner. No wire tapping needed.

I am considering running all the way to the back now because I have two cameras to wire. I dont think my '12 glk has a glove box cig lighter... or I didnt look well enough :)

anyways, is there a pic of A pilar removed? I am scared as hell of touching trim parts with the airbag symbol. and I will have to lose the a pillar trim either way (glove box or trunk fuse box)

What kind of detector are you guys running? Over the last year or so, as more and more radar-equipped cars get introduced, my always-reliable Escort has turned from a radar detector to a new-car detector. It's pretty much useless any more. Are there any good solutions out there?

My V1 has a mode that filters out all of that junk.

The V1 with:

for android:

https://play.google.com/store/apps/d...kyl.yav1&hl=en

for iPhone:

https://itunes.apple.com/us/app/stea...792567084?mt=8


That will filter out all the bull**** and give you the cops only.

Mine doesn't and I hate it. Guess it's time to send it in for a software update again. Good to know it works well.

Yeah I should have mentioned that. I had to send it back for warranty work about a year ago, and they updated everything to the latest spec. The new mode does a great job filtering out junk without affecting its ability to detect the real thing.

I haven't updated my V1 since I bought it in 2003, lol! Works fine as is, but may still pay the few hundred for the update.