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I've had it with the power cord from my radar detector hanging down, getting in my way and plugged into the cigarette lighter socket. The detector is below the mirror and the white/gray wire replacing the usual power cord may be further tucked away so it is not too noticeable.
This wiring is done so the radar detector is active when the key is turned to ON. Some of the detail on how to physically make the connection to the power wire identified is left to your ingenuity.
The power lead is picked up from the sun roof power control wires at the plug to the motor assembly for the sun roof. This lead is a power wire that is hot in ON and START. These wires can be accessed from the center front roof panel containing the sun roof and courtesy switches and sun glass compartment. It is recommended to remove the negative battery terminal before working with the electrical system of the vehicle.
Gaining Access
Open the sun glass compartment and pull down the front of the inner felt liner. Remove the two screws.
Screws in the front portion (closest to the windscreen)
Pry down the light cover/lens.
Be careful and use a thin flathead screw driver to not mar the surface.
Remove the screw next to the bulb.
If you are clumsy remove the light bulb (cylindrical tube with metal on both sides) you will save yourself from cleaning up a mess.
Once the 3 screws are removed, you can pull down the front a little and slide the unit down and toward the front. There are 3 clips on the rear edge that will pull out from behind the inner roof lining. Once the assembly is down, disconnect the 2 connectors and place the assembly aside.
The blue connector tucked up inside the roof liner is connected to the motor assembly (Moon Roof Control ECU).
Be careful and take your time. Patience is key!
I did get this connector out and back without taking down the roof liner. This was the most difficult part of the entire procedure. Using a small screwdriver to release the latch and then backing out the plug.
The blue connector is shown below. The wire tapped into is the Blk/Red on pin #8 which is in the top row, third from the left as shown here. You can test this pin: +12v will be there when the key is turned on.
This is the cable pulled out a little, again take care it will be a PITA if you tear it!
See the guide below to find out which pin is always hot. The way I prefer it is hot when in start/run so when you turn off your Lexus it turns off too!
I'll be using #8
Once reassembled, the wire can be run from the edge of the center roof console. While there may be other ways to accomplish this and placement of the wiring, this seemed to be the fastest with least work. (If you're really picky like me see below the last image for tips on how to conceal the cable)
I'm a picky person though and what I would do is find a way to be able to run the wire through the little conduit/port area for the mirror wiring and make a small incision on the cover so the wire can be placed in the groove without it being clamped.
Once you remove this cover you will probably be able to dig around the front area of the dome light recessed fitting area and find the conduit where the wire is sent from the recessed fitting to the mirror. Slide the cable through and cut a little sliver of the cover out so the wire isn't being clamped, but can sit in. Replace the cover.
Note: I have shamelessly stolen the images from a long gone blog and a YouTube video. If I violate your copyright let me know. Thanks!
Last edited by jgoorn; 09-11-14 at 09:30 PM.
Reason: Add, precision fitting guide
Good idea... I wired in my Garmin Nuvi GPS today like this. Except i didnt disconnect the plug, I tapped into the wires that are in plain view. Only the wire for constant power and ground is there. I wired in an extra 12v lighter socket so the unit just plugs in and also because the Garmin actually uses a built in converter to 5 volts so it must be plugged in to a typical 12v plug. Very clean install and no more hanging cord which i hated.
Good idea... I wired in my Garmin Nuvi GPS today like this. Except i didnt disconnect the plug, I tapped into the wires that are in plain view. Only the wire for constant power and ground is there. I wired in an extra 12v lighter socket so the unit just plugs in and also because the Garmin actually uses a built in converter to 5 volts so it must be plugged in to a typical 12v plug. Very clean install and no more hanging cord which i hated.
09-11-14, 09:09 PM
Hardwiring Radar Detector to RX300
