Switched power source?
 

I installed a BEL STiR radar detector in my 2013 GS350 and need a switched 12v power source. I assumed (incorrectly, as it turns out) that I could just connect a power lead to a presumably switched circuit at the fuse box. Unfortunately, every circuit is energized all the time (I assume because the car is CAN-bussed; there must be relays or switches at each device), and I would have to remember to turn the unit on an off manually every time I drive. Not going to happen.

Are there any techs or electronics whiz kids who can guide me to the simplest actually-ignition-switch powered place to tap in to? It seems easiest to me to simply tap into one of the 12v pwer adapters, but I would rather not take too much of the console apart if I can help it, to avoid rattles. Perhaps a relay of my own (I would need specs and a wiring diagram)

Any help would be appreciated. Thanks!

is the home link system switched?

Please forgive my ignorance; I am new to Lexus. I am not familiar with the term home link system.

I believe you should be able to tap it into the power wire on the rearview mirror like rominl was saying with the home link (garage, gate opener buttons on the rearview mirror). Just make sure to ground the radar detector. Sorry I haven't done it yet on the GS350, so no step by step. Someone else can chime in on that as I am sure many on this forum have already hardwired the radar detectors.

If you have a valentine one the easiest way is to buy the power connector that plugs into your OBD port. Gives you switched 12v power and has a dial that let's you limit Radar warnings under a certain Speed. Works like a charm

Not sure how to get to the home Link wire without needing to run a wire up to the header (I would like to disturb as little of the trim as possible).

I like the idea of the OBD, but I am unfamiliar with the power adapter you refer to. Does anyone know the pinout on the OBD port? Perhaps a direct tap on the OBD power, if the proper wire is known?

Another thought I had was to simply tap into the front power port in the console, which appears to be switched. I've popped out the unit, but the wires are terribly short (perhaps one more inch, and it would be easy).

I have hard wired a Valentine into all the recent cars I've owned

All of them have had Homelink and the Homelink circuit was hot all the time

so I rewired the Homelink in all them to be switched, so that if the car is in the driveway and someone breaks into the car, they cannot open the garage door and get into the house

I have used this kind of fuse piggy-back


I found and bought one on that big auction site that fits the mini fuses the Lexus uses

couldn't find that small version at local auto parts stores

in the small fuse box above the drivers left knee, I found a circuit that is switched, all others I tried are hot all the time

I can look if you wish and see which fuse number I used, but it was easy to find with a circuit tester

search the forum too, because there is a thread showing how to get 12v from the wiper sensor plug behind the mirror

I looked at that and didn't want to mess with the plastic trim because I was afraid I would break something

I hard wired my V1 into my rain sensor with a "mirror tap". You can look at it at . The rain sensor is a switched circuit so you won't need to make sure you shut it off.

i don't know about the 4gs, but on all my previous lexus, i believe the home link are switched. very weird as most other cars the home link is always hot.

Regardless of which car i'm in (either the 2011 RX or 2013 GS), I typically open the garage door before I start the car using the buttons on the mirror (in the GS) or the overhead console (in the RX), so they have to be live with the car off. In either the RX or GS, my procedure is the same. I could be wrong (not the first time.....probably not the last) but I believe that's the homelink system so it's probably not switched.

crap now you make me wonder and want to test in our car. i might have mixed it up with our bmw and mb :( getting too old...

Nealb's solution was the one that worked. I had checked the fuses on the right side dashboard and the right side engine (all of which, as it turns out, are powered all the time). However, as Nealb suggested, there are several switched circuits in the left side fuse panel. Everything now works fine, and my completely concealed radar/laser detector/laser blocker setup is complete.

I knew that the combined wisdom of the group would have the answer. Thanks to everyone for the help!

Lexus HomeLink stays on, the Germans are switched

i have the V1 with the obd saavy and it does not turn off when i turn off the car. Does yours turn off?

It sounds like you already got it working to your liking. As someone who has installed Beltronics hidden radar detectors in five vehicles (four my own, including my 2013 GS F Sport), I have always tapped into the 'cigarette lighter' power for every installation and have never had an issue.

The important thing is to be careful, take your time, don't break any clips (sounds simple enough but you'd be surprised), and to do the job right (which includes taping down anything that might rattle).