Switched 12V

[hjk3]

I am in need of a switched 12volt source for radar detector hard wiring. I have searched all over the internet (and all over the car also) for a likely source. Any ideas? Failing that, any sources to trigger a relay? Thanks.

hjk3

[Loren]

Isn't there a 12 volt socket in the passenger footwell?

[WolfgangK]

Yes, there is a socket, but it's not switched (it does not even turn off after 2hours like i.e. the instrument cluster). I also tried to find one (987), but I gave up after 3 hours and after having dismantled half of the car....

[rgcohen]

I, too, have searched unsuccessfully online to find a switched source of current for a radar detector. In my M3 the Homelink unit has switched current located nearby the rear view mirror and overhead light unit. It was a simple matter to use a 3M tap and thread the power cord out just to the side of the mirror, right where you would want it. It is so much more elegant than tapping current from the fuse box or running up from one of the sockets.

Has anyone accessed the wiring going to the Homelink and determined the correct wire? One of the forum postings elsewhere noted that switched power should be green with a black stripe. As my car has not yet been delivered I am unable to attempt the disassembly of the light or Homelink units. Anyone tried that and had a look?

[Loren]

I, too, have searched unsuccessfully online to find a switched source of current for a radar detector. In my M3 the Homelink unit has switched current located nearby the rear view mirror and overhead light unit. It was a simple matter to use a 3M tap and thread the power cord out just to the side of the mirror, right where you would want it. It is so much more elegant than tapping current from the fuse box or running up from one of the sockets.

Has anyone accessed the wiring going to the Homelink and determined the correct wire? One of the forum postings elsewhere noted that switched power should be green with a black stripe. As my car has not yet been delivered I am unable to attempt the disassembly of the light or Homelink units. Anyone tried that and had a look?

If your car has the anti-dazzle (inside) rearview mirror there is switched 12 volts on that - Black/Orange wire.

[hjk3]

Loren,

It would be quite difficult to hide the V-1 transformer thingy anywhere near there. Is there any problem tapping off the fuse panel? There are unused slots that have 12v power. Would this cause CAN bus problems?

[Loren]

Yes, you could come off the fuse panel. Radio Shack has jumper/tap that makes it very easy (Radio Shack #270-1204). This is a jumper but you get the idea...

(Images courtesy of Yoseif)

[arctic silver]

I installed my V1 radar detector just to the right of the rear view mirror, modifing the winshield mount by taking off the suction cups and replacing them with double-sided take. It is now firmly positioned in the right place (rear horn can see out the rear window) and quite out of the way. You can easily find switched 12v at the fuse panel (either an unused fuse holder (V1 power wire is already fused) and just stick in the wire where one end of the fuse would go, or stick it in beside a used switched fuse slot). There is a nice slot right at the top of the windshield where hide the wire (I used a few pieces of black foam rubber after the wire was placed there to make sure it stayed in place (everything is hidden from view), then run the power wire down the same slot on the left, tuck in out of sight and down to the fuse panel. It is easy and totally invisible with nothing to modify.

arcticsilver

I am in need of a switched 12volt source for radar detector hard wiring. I have searched all over the internet (and all over the car also) for a likely source. Any ideas? Failing that, any sources to trigger a relay? Thanks.

hjk3

[Westcoaster]

Loren,

It would be quite difficult to hide the V-1 transformer thingy anywhere near there. Is there any problem tapping off the fuse panel? There are unused slots that have 12v power. Would this cause CAN bus problems?

I am looking for a 'clean' switched 12v source as well. By clean, I mean each time I scoped a line it is a squarewave not a solid 12v. This drives relays to buzz instead of a solid on condition.

Aren't all of the connections in the fuse panel 'on' all of the time?

Is there a place on the light switch that could be used to trigger a relay, say when truning on the park lights?