# 12V switched and key sense wire



## phool27 (May 2, 2002)

As most of you know, the Monsoon Double DIN radios obtain their switched 12V line from the CAN-BUS. When planning for a replacement HU, you will need to get your switched 12V from somewhere else in the car since it's not available at the stock wiring harness.
One result of the Double DIN Monsoon receiving its switched power in this way, is that the radio will continue receiving power until the key is removed from the ignition. In other words, if you have the radio on and turn the car off and leave the key in the "OFF" position, the radio will remain on. It is only after you remove the key from the ignition that the radio shuts off.
I would like to retain this feature with my new head unit. After researching this topic for a couple of days, I have found a variety of answers that don't really add up to anything conclusive when considered together. I'm hoping someone here can clarify this.
Here's what I've heard and know to be true:
1. If you want to retain the "power off when key removed" feature of the Double DIN Monsoon, you can tap into the key sense wire (brown/red) at the ignition switch (courtesy of kwalton):









2. You can use a ring terminal at 75x (black/yellow) on the distribution center for the switched 12V. This is located behind the driver side dash trim, just above the dead pedal (again, thanks to kwalton):









3. You can use a VW repair wire for the fuse block (00 979 227) on an empty block in the fuse box to grab switched 12V. For those of you with a manual tranny, #31 should be open as it is reserved for the automatic transmission.
I went ahead and did a test run using #3 above, and unfortunately the "power off when key removed" feature *WAS NOT* retained.
--------------------------------------
So here are my questions:
1. Will #2 listed above (75x at distribution center) allow me to retain the "power off when key removed" feature?
2. Will any other fuse block allow me to retain this feature? I have #30 (usually reserved for the sunroof) and #44 (usually reserved for heated seats) currently open.
3. Or, do I just need to suck it up and accept the fact that the only way to retain "power off when key removed" is to tap into the key sense wire at the ignition switch?
If you answer "yes" to question #3 I guess I can call it a day as I have no desire to tap into this wire...
Thanks in advance.
- Nick


_Modified by phool27 at 8:14 AM 5-8-2005_


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## GTIVDUB (Apr 25, 2004)

*Re: 12V switched and key sense wire (phool27)*

Good question, very well written. Unfortunatly I do not know the answer, hopefully you get a good response because I would like to know the answer too. That is a nice feature of the stock setup that I would like to keep also. Why not tape the brown/red wire?


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## phool27 (May 2, 2002)

*Re: 12V switched and key sense wire (GTIVDUB)*

Well I guess I'm not the only one with questions...
Anybody with answers?


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## phool27 (May 2, 2002)

*Re: 12V switched and key sense wire (GTIVDUB)*


_Quote, originally posted by *GTIVDUB* »_Why not tape the brown/red wire?

I just want to go with a clean install which leaves little trace of itself if I ever decide to go back to stock somewhere down the road. I already have to use a tap for the illumination but I don't have any other options there....


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## crnacnac (Aug 3, 2004)

fuse #10 will get you what you're looking for. Remove the fuse box cover (left side dash), remove side dash trim, remove two torx head screws that hold the fuse box to the dash, pop the cover off the back of the fuse box, look at fuse 10 (red mini fuse) so you can identify the wires going to the fuse terminals, tap into the wire leaving the fuse so your circuit will be protected. Sorry, no pics or wire color codes. I will try to post those later.


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## phool27 (May 2, 2002)

*Re: (crnacnac)*


_Quote, originally posted by *crnacnac* »_fuse #10 will get you what you're looking for. Remove the fuse box cover (left side dash), remove side dash trim, remove two torx head screws that hold the fuse box to the dash, pop the cover off the back of the fuse box, look at fuse 10 (red mini fuse) so you can identify the wires going to the fuse terminals, tap into the wire leaving the fuse so your circuit will be protected. Sorry, no pics or wire color codes. I will try to post those later.

Jon -
Thanks for the tip...I remember reading about this somewhere as well...I forgot to mention this above.
I was hoping that there was another alternative since #10 isn't open and would require a tap. Also, I'm not so crazy about messing with the Engine Control Module...
Any other suggestions?


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## crnacnac (Aug 3, 2004)

I've done five installs using this method with no problems at all. You can add a relay to take any additional load that you would put on the circuit or you can grab it at the ignition switch as posted earlier (which I think is more work dealing with the column covers)


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## phool27 (May 2, 2002)

*Re: (crnacnac)*


_Quote, originally posted by *crnacnac* »_I've done five installs using this method with no problems at all. You can add a relay to take any additional load that you would put on the circuit or you can grab it at the ignition switch as posted earlier (which I think is more work dealing with the column covers)

Jon - 
Thanks again...I appreciate the feedback...sounds like you have some experience in this area and it's great to hear that this has been successful for you in 5 different installs...I definitely will consider this in my options.
Anyone else care to chime in?


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## kwalton (Sep 3, 2001)

*Re: 12V switched and key sense wire (phool27)*


_Quote, originally posted by *phool27* »_As most of you know, the Monsoon Double DIN radios obtain their switched 12V line from the CAN-BUS. When planning for a replacement HU, you will need to get your switched 12V from somewhere else in the car since it's not available at the stock wiring harness.
One result of the Double DIN Monsoon receiving its switched power in this way, is that the radio will continue receiving power until the key is removed from the ignition. In other words, if you have the radio on and turn the car off and leave the key in the "OFF" position, the radio will remain on. It is only after you remove the key from the ignition that the radio shuts off.
I would like to retain this feature with my new head unit. After researching this topic for a couple of days, I have found a variety of answers that don't really add up to anything conclusive when considered together. I'm hoping someone here can clarify this.
Here's what I've heard and know to be true:
1. If you want to retain the "power off when key removed" feature of the Double DIN Monsoon, you can tap into the key sense wire (brown/red) at the ignition switch (courtesy of kwalton):









2. You can use a ring terminal at 75x (black/yellow) on the distribution center for the switched 12V. This is located behind the driver side dash trim, just above the dead pedal (again, thanks to kwalton):









3. You can use a VW repair wire for the fuse block (00 979 227) on an empty block in the fuse box to grab switched 12V. For those of you with a manual tranny, #31 should be open as it is reserved for the automatic transmission.
I went ahead and did a test run using #3 above, and unfortunately the "power off when key removed" feature *WAS NOT* retained.
--------------------------------------
So here are my questions:
1. Will #2 listed above (75x at distribution center) allow me to retain the "power off when key removed" feature?
2. Will any other fuse block allow me to retain this feature? I have #30 (usually reserved for the sunroof) and #44 (usually reserved for heated seats) currently open.
3. Or, do I just need to suck it up and accept the fact that the only way to retain "power off when key removed" is to tap into the key sense wire at the ignition switch?
If you answer "yes" to question #3 I guess I can call it a day as I have no desire to tap into this wire...
Thanks in advance.
- Nick

_Modified by phool27 at 8:14 AM 5-8-2005_

well since i seem to be the photo sponsor of this thread (insert sarcasm) i will answer the question. the only way that you can retain power when the key is off is to tap the ignition lead from your new radio into the constant 12v wire. this will mean that you will have to turn on and off the radio manually everytime you use the car. the key sense wire gives you switched 12v whenever the key is inserted and keeps 12v until the key is removed.
a few other options you could have:
1. wire in a few relays that keep your radio powered until a door is opened after you turn the car off (think newer gm cars.)
2. hook up the radios igntion input up to an aftermarket alarm so you can turn it on and off with the remote. i have this feature on my viper 791, works great. 
i don't know if this gives you the answers you are loking for but maybe it helps.


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## phool27 (May 2, 2002)

*Re: 12V switched and key sense wire (kwalton)*


_Quote, originally posted by *kwalton* »_well since i seem to be the photo sponsor of this thread (insert sarcasm) i will answer the question. the only way that you can retain power when the key is off is to tap the ignition lead from your new radio into the constant 12v wire. this will mean that you will have to turn on and off the radio manually everytime you use the car. the key sense wire gives you switched 12v whenever the key is inserted and keeps 12v until the key is removed.
a few other options you could have:
1. wire in a few relays that keep your radio powered until a door is opened after you turn the car off (think newer gm cars.)
2. hook up the radios igntion input up to an aftermarket alarm so you can turn it on and off with the remote. i have this feature on my viper 791, works great. 
i don't know if this gives you the answers you are loking for but maybe it helps. 

Hey Kevin,
Thanks for chiming in. When you said:

_Quote, originally posted by *kwalton* »_well since i seem to be the photo sponsor of this thread (insert sarcasm) i will answer the question. the only way that you can retain power when the key is *OFF* is to tap the ignition lead from your new radio into the constant 12v wire.


Did you mean to say *OUT*, as in removed from the ignition?
I definitely don't want run my switched 12V to a constant 12V as I don't want to deal with having to turn the radio off everytime I leave the car.
I definitely understand the key sense wire tap thanks to your multiple posts on this topic in the past.








Thanks for the two additional options. I especially like #1. It got me thinking about how our windows. You might have noticed that after turning the car off and leaving the key in the ignition, your windows will continue to have power. As soon as you open your door, their power is cut.
Now I don't have a sunroof and therefore, as I said above, I have fuse #30 available. I asked a friend who does have a sunroof to test it out for me and he stated that it behaves the same way as the windows: power with key in off position until door is opened.
So I'm wondering, perhaps if I use #30, my radio will behave the same way. But perhaps this function is due to a relay further down the line on the sunroof and window wiring harness.
Who knows? Not I...
But I plan on testing it out later tonight and will post my findings...
Thanks again for your help. http://****************.com/smile/emthup.gif 
_Oh yeah, one last thing....I actually saved those images a while back and am hosting them on my server...so you don't have to worry about bandwidth issues...and since you're the sponsor, what kind of kickbacks do I see?_












_Modified by phool27 at 8:57 AM 5-9-2005_


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## kwalton (Sep 3, 2001)

*Re: 12V switched and key sense wire (phool27)*

the function that your are tlking about when the windows stay powered up is called RAP (retained accessory power.) i have neer tried but tapping into the power for the non-existant sunroof may be a good idea. let me know how it turns out. 
i was just joking about the pics; i am just happy that people are searching for info and finding them. after all that's why i took them.


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## phool27 (May 2, 2002)

*Re: 12V switched and key sense wire (kwalton)*


_Quote, originally posted by *kwalton* »_the function that your are tlking about when the windows stay powered up is called RAP (retained accessory power.) i have neer tried but tapping into the power for the non-existant sunroof may be a good idea. let me know how it turns out. 
i was just joking about the pics; i am just happy that people are searching for info and finding them. after all that's why i took them.
















Thanks again...going to five this a try in a little bit...


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## honesttussey (Jul 26, 2003)

*Re: 12V switched and key sense wire (phool27)*

You all seem to know alot about 12V and wires in the dub so here is my question? Is ACC line a constant 12V source once key is turned halfway? I just need a constant 12v source for my HU lights as the backlight wire on the harness doesn't provide a constant 12v so my lights flicker on the HU.


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## kwalton (Sep 3, 2001)

*Re: 12V switched and key sense wire (honesttussey)*

your radio is probably flickering due to a bad ground. try running a new one to a factory boly and see if it clears up.


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## mtltdi (Apr 10, 2003)

*Re: 12V switched and key sense wire (honesttussey)*


_Quote, originally posted by *honesttussey* »_You all seem to know alot about 12V and wires in the dub so here is my question? Is ACC line a constant 12V source once key is turned halfway? I just need a constant 12v source for my HU lights as the backlight wire on the harness doesn't provide a constant 12v so my lights flicker on the HU.

It's flickering because you're in the dimmer wire, you need the 12v wire in the light switch for headunit lighting.. http://****************.com/smile/emthup.gif


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## MYK (Nov 24, 1999)

*Re: 12V switched and key sense wire (mtltdi)*

my eclipse used to do the same thing with the illumination hooked up. I can't remember if our cars have a separate dimmer and straight illumination wire when the lights are on. some cars have both, some only have a dimmer. the eclipses are extremely sensitive to the dimmer input. I ended up just not using it, when i had mine.


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## RQtechVR6 (Oct 30, 2002)

*Re: 12V switched and key sense wire (MYK)*

OMG I love you for this!
I blew up on the clowns at best buy for telling me, it's normal for these cars to have to turn your deck on and off as you enter/exit the car.
Of course i didn't know how to fix this either, but there's supposed to be proffessionals!








Doing this tomm.


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## CMihalcheon (Jan 29, 2007)

*Re: 12V switched and key sense wire (RQtechVR6)*

I know this post is ancient news now, but did the Sunroof fuse give you RAP power for your stereo? Has anyone used this fuse? I am installing my stereo this weekend, and I would like to use fuse #30, if it gives RAP power. Thanks


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## elio (Nov 15, 2006)

*Re: 12V switched and key sense wire (CMihalcheon)*

Hi friends. This thread is very useful for my needs, but I have some doubts:
1.- Option #2 talking about 75X blk/ylw wire. Is this wire simply a switched 12v point? I mean when key is back to turn off position, the 75X goes off, inclusive retaining key inside the ignition switch. Right?
2.- Ok now in the engine bay, specially near battery or that side. I saw many 12v constant wire in the fuse block over battery, but does exist a similar switched wire like 75X around this area?
For you info my car is a 2002 VW Golf GTi, I mean a MK4. I ask because I don't have the Bentley manual yet, then I don't have circuit diagrams.
I really appreciate your help.
Thanks,


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## pwnt by pat (Oct 21, 2005)

*Re: 12V switched and key sense wire (elio)*

All of the fused wires coming off of that distro are 12v constant only. You have to tap the 75, fuse box, or ignition column.


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## CMihalcheon (Jan 29, 2007)

*Re: 12V switched and key sense wire (pwnt by pat)*

F.Y.I for anyone who cares, the sunroof fuse won't work for a stereo install on a car that does not have a factory sunroof, because there is no power wire going to the fuse


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## D03GLIR (Oct 21, 2004)

*Re: (crnacnac) Fuse #10 it is....*

BFTD-
Fuse # 10 it is
#30, X75 or #24 (Crutchfield instruction), 25 wont give you retained accessory power (RAP).
I modified the fuse tap clip from Crutchfield (bent piece of brass strip w/ male terminal) to fit the smaller fuse vs. tying into the wire behind. Only visible if the fuse cover is opened.
BTW- Fuse 30 (Sunroof) is constant 12V, Switching must be further in the circuit).


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## blazerpounds (Mar 19, 2008)

*Re: 12V switched and key sense wire (RQtechVR6)*

best buy doesnt sell clowns yet
without
Until they can complete door locks on an 08 sebring without calling my store I refuse to believe this.


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## BoostThirsty2001 (Aug 2, 2008)

*Re: 12V switched and key sense wire (blazerpounds)*

Please help me out. For some reason this brown and red 12V switched wire isnt recieving power with my stock radio set up. I have checked all fuses inside the car and all are fine. The radio wont even turn on with the key anymore. Please.... this is killing me because I have plans for this wire... I need to tap it. Any ideas???










_Modified by BoostThirsty2001 at 5:11 AM 5-30-2009_


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## evan224 (May 30, 2009)

I am having trouble even getting power to my amp from option 2. I don't know why because the wire from the amp to the battery is fine and the other wire is grounded. Any help on this damn 12v key wire?


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## BoostThirsty2001 (Aug 2, 2008)

*Re: (evan224)*

i tapped my brown/red wire and ran it to the 75x terminal. No problems and everything I had problems with is fine again


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## italgti (Jul 18, 2007)

*Re: 12V switched and key sense wire (pwnt by pat)*


_Quote, originally posted by *pwnt by pat* »_All of the fused wires coming off of that distro are 12v constant only. You have to tap the 75, fuse box, or ignition column.

So if you tap the red acc wire from the aftermarket deck into the 75x, you will retain the feature of the radio turning off once the key is pulled?


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## piston (Oct 17, 2008)

*Re: 12V switched and key sense wire (italgti)*


_Quote, originally posted by *italgti* »_
So if you tap the red acc wire from the aftermarket deck into the 75x, you will retain the feature of the radio turning off once the key is pulled? 

I don't see/have that terminal block on a MKV GTI.


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## piston (Oct 17, 2008)

MKV models:
Well, the Bentley manual states that X75 should be on the J519 control module but I checked all wires and they are either 12v constant or 12v when ignition on only.
I tried to get the fuse box open but the fuse box harnest is tied/strapped and I can't get to the back of it.
Anyone have any ideas/solutions to get the 12v switched/key sense wire on a MKV Gti/Rabbit ?

_Modified by piston at 2:20 PM 6-6-2009_


_Modified by piston at 2:20 PM 6-6-2009_


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## joshuo (Jun 16, 2008)

*Window Circuit*

Try the Power windows Circuit. that stays active until you open a door... http://****************.com/smile/emthup.gif 
It's fuse #5, 7.5A, conv. electrics, navi, parking aid. 
This is on my *MK1 Audi TT*, which should be the same as the MK4 Golf wiring (all the previous mentioned fuses and connections are the same)


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## piston (Oct 17, 2008)

*Re: Window Circuit (joshuo)*


_Quote, originally posted by *joshuo* »_Try the Power windows Circuit. that stays active until you open a door... http://****************.com/smile/emthup.gif 
It's fuse #5, 7.5A, conv. electrics, navi, parking aid. 
This is on my *MK1 Audi TT*, which should be the same as the MK4 Golf wiring (all the previous mentioned fuses and connections are the same) 

On the MKV, fuse #5 and #10 are not wired.(I finally got the fuse box rear cover off and checked.)
I also checked the steering wheel ignition and no red/brown wire.

If someone can confirm a known switched 12v on the MKV that only goes off when the key is removed(like OEM), please let me know.


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## BoostThirsty2001 (Aug 2, 2008)

*Re: 12V switched and key sense wire (italgti)*

No, in order to retain this feature you have to find the brown/red wire on the stock wiring harness. Its in the top corner of all the wires going into the radio. tap and run that to you're 75x terminal and youre aftermarket HU will shut off once the key is pulled. Mine did.


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## piston (Oct 17, 2008)

*Re: 12V switched and key sense wire (BoostThirsty2001)*


_Quote, originally posted by *BoostThirsty2001* »_No, in order to retain this feature you have to find the brown/red wire on the stock wiring harness. Its in the top corner of all the wires going into the radio. tap and run that to you're 75x terminal and youre aftermarket HU will shut off once the key is pulled. Mine did.

You did this on a MKV VW ?


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## italgti (Jul 18, 2007)

*Re: 12V switched and key sense wire (BoostThirsty2001)*


_Quote, originally posted by *BoostThirsty2001* »_No, in order to retain this feature you have to find the brown/red wire on the stock wiring harness. Its in the top corner of all the wires going into the radio. tap and run that to you're 75x terminal and youre aftermarket HU will shut off once the key is pulled. Mine did.

brown with a red stripe or red with a brown stripe?


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## vdubnick (Nov 29, 2004)

if you want to have an acc feature much like the older switched power units, where the radio stayed on until you pulled the key out, but did not come on until you turned the key you will need two relays. You could just wire the switched wire to the (+) keysense, but that would get anoying as the radio would come on each time the key is put in, before turning it.

.
.
So with two bosch style relays, and one diode (you can use any size, 1amp is fine) you would wire as such.
relay #1
85- (-) terminal 87 of relay 2
86- (+) acc/or ign. with a diode in between relay and acc/ign wire (post 75x) with the stripe closest to relay
30- (+) output to radio, and looped to terminal 86
87a- not used
87- (+) constant fused 12v 
relay #1
85- (-) ground
86- (+) keysense
30- (-) ground
87a- not used
87- (-) to terminal 85 of relay 1
This setup will turn the radio on like normal with the ignition, but then allow the radio to stay on when the key is off, until the key is removed.


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## vdubnick (Nov 29, 2004)

*Re: 12V switched and key sense wire (phool27)*


_Quote, originally posted by *phool27* »_As most of you know, the Monsoon Double DIN radios obtain their switched 12V line from the CAN-BUS. When planning for a replacement HU, you will need to get your switched 12V from somewhere else in the car since it's not available at the stock wiring harness.
One result of the Double DIN Monsoon receiving its switched power in this way, is that the radio will continue receiving power until the key is removed from the ignition. In other words, if you have the radio on and turn the car off and leave the key in the "OFF" position, the radio will remain on. It is only after you remove the key from the ignition that the radio shuts off.
I would like to retain this feature with my new head unit. After researching this topic for a couple of days, I have found a variety of answers that don't really add up to anything conclusive when considered together. I'm hoping someone here can clarify this.
Here's what I've heard and know to be true:
1. If you want to retain the "power off when key removed" feature of the Double DIN Monsoon, you can tap into the key sense wire (brown/red) at the ignition switch (courtesy of kwalton):









2. You can use a ring terminal at 75x (black/yellow) on the distribution center for the switched 12V. This is located behind the driver side dash trim, just above the dead pedal (again, thanks to kwalton):









3. You can use a VW repair wire for the fuse block (00 979 227) on an empty block in the fuse box to grab switched 12V. For those of you with a manual tranny, #31 should be open as it is reserved for the automatic transmission.
I went ahead and did a test run using #3 above, and unfortunately the "power off when key removed" feature *WAS NOT* retained.
--------------------------------------
So here are my questions:
1. Will #2 listed above (75x at distribution center) allow me to retain the "power off when key removed" feature?
2. Will any other fuse block allow me to retain this feature? I have #30 (usually reserved for the sunroof) and #44 (usually reserved for heated seats) currently open.
3. Or, do I just need to suck it up and accept the fact that the only way to retain "power off when key removed" is to tap into the key sense wire at the ignition switch?
If you answer "yes" to question #3 I guess I can call it a day as I have no desire to tap into this wire...
Thanks in advance.
- Nick

_Modified by phool27 at 8:14 AM 5-8-2005_

please dont tell me that that black loom in the corner by the foot rest is your power wire....


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## BoostThirsty2001 (Aug 2, 2008)

*Re: 12V switched and key sense wire (italgti)*

i did this in a MKIV. Brown wire, red stripe.


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## dckeener (Jan 10, 2005)

*Re: 12V switched and key sense wire (phool27)*

Didn't feel like reading all the answers. I have a double din kenwood. I had the power hooked up to the big fuse box and the radio would only stay on with the key on. I then hooked the switched power wire to the one pictured in the steering column, and it stays on till i pull the key out completely. this was the only way I could figure out.


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## vdubnick (Nov 29, 2004)

^ quit being a winey lazy ass.


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## vwraddo93slc (Jan 2, 2007)

*Re: 12V switched and key sense wire (phool27)*

gonna do this i am tired of turning off the radio when i shut the car down


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## italgti (Jul 18, 2007)

*Re: 12V switched and key sense wire (dckeener)*

did you have to remove the steering wheel to get to the key sense wire?


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## vdubnick (Nov 29, 2004)

^ depends on how smart you are.


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## italgti (Jul 18, 2007)

*Re: (vdubnick)*

please enlighten me http://****************.com/smile/emthup.gif


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## vwraddo93slc (Jan 2, 2007)

*Re: 12V switched and key sense wire (phool27)*

i did option number 1 it worked out great i put a fuse in the circuit a very low amp one i actually used a 1 amp fuse for it all the stuff i needed i picked up a radio shack cheap and i didn't actually splice into it i tapped into it http://****************.com/smile/emthup.gif


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## vwraddo93slc (Jan 2, 2007)

*Re: (italgti)*

no i didn't have to when i did it. i just took the top of the cover off of the column. removed the kick panel so i could run the fuse to my fuse, to the fuse panel in case i needed to ever change it i didn't have to take the car apart again.


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## MI_canuck (Dec 21, 1999)

*Re: Success!!! Key sensing circuit works like a charm!!!*

Success!!! http://****************.com/smile/emthup.gif
I was thinking of tapping off the back of some pins of the fuse box.... But after going through a few of the posts on 12V switching and the Alpine installs that others have done in their MKIV's... I decided to try the "key sensing" method
So I basically tapped into the small red/brown wire as shown in the pics of those posts... I put in an inline 10A fuse between the splice and the head-unit, just to be safe and not fry the factory wiring if something goes a miss down the road wit the head-unit...
BINGO!!! Works like a CHARM!!! http://****************.com/smile/emthup.gif The radio powers up when the ignition is turned on (key on, engine off)... Just as expected. But the beauty is that when turning the key back to the OFF position... bom-ba-ba-BOM!!!







The radio stays ON... just like the factory unit did... And shuts off once the key is removed completely from the ignition cylinder... So you don't have to turn the radio off manually. When the key is put back in, the radio doesn't come on until you turn the key to the ACC or ON positions. Beauty!!! The only thing it doesn't do is have the ability to be turned on even with no key in the ignition like the factory unit, but that's a minor issue that I can live with.








As for the dimmer line off the head-unit, which on Alpines is really one a 12V switched source to trip the dimmer feature on the head-unit to go the dim setting (there is only dim or bright) for when you have the lights on (ie. at night) so the unit isn't blasting your eyeballs with the super bright setting. But the bright mode is good during the day.
So what I ended up doing for this is just tapping the dimmer wire (the orange wire from the Alpine) to the grey/blue dimmer wire off the headlight switch. I decide to splice into it from the headlight switch rather than from the dimmer knob, simply due to accessility... was MUCH easily to pull out the switch and work that way... Could splice in a solder much more easily. So that also works like a charm!! Light switch off, headunit's lights are BRIGHT.... when switch turned to park lights (I have the Euro switch) or headlights ON, the headunit goes to dim mode. And back to bright when the headlight switch is turned back to off. The dimmer knob for the instrument lights doesn't dim the headunit lights (Alpines can't be gradually dimmed it seems - something to do with either the LED's or simply how it's wired interally... don't know...). And I only get the flicker problem with the headunit's light if I'm at the very lower dimmer setting... If I nudge it up a bit, the problem is solved. So I just need to back off from the lowest setting if I run the dimmer switch on long night drives - which is still very dim.
Here are some pics... sorry about the quality... was dark by the time I got done... The tape's a bit sloppy but it's soldered nice and solid underneath - I think the tape came loose from the heat of the solder (I didn't let cool down enough... I was in a rush







... I'll retape in the morning...)

























I'm glad I came across this method of wiring the 12v switched (since there isn't anything in the radio pocket on the CAN-bus cars... 

cheers


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## MI_canuck (Dec 21, 1999)

*Re: (vdubnick)*


_Quote, originally posted by *vdubnick* »_if you want to have an acc feature much like the older switched power units, where the radio stayed on until you pulled the key out, but did not come on until you turned the key you will need two relays. *You could just wire the switched wire to the (+) keysense, but that would get anoying as the radio would come on each time the key is put in, before turning it.*


Wrong-o!.... I just did the install in my MKIV... when tapping/splicing into the key sensing circuit off the column/ignition switch (red/brown wire - the small one in the upper left, not the larger one - I tested with a meter just to make sure), the radio stays on when ignition is turned to the OFF position but the key left IN... The radio then turns off once key is removed... BUT... the radio DOES NOT turn on again until the key is turned to at least the ACC position (not a hard detent but the position between OFF and KEY ON-ENGINE OFF)... works like a champ! Didn't need any relays or any of the sort to do exactly what you describe... I just tapped into the red/brown wire, along with an inline 10A fuse just as a precaution... Everything else wired as normal... Bob's your uncle! http://****************.com/smile/emthup.gif

cheers


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## vdubnick (Nov 29, 2004)

^ yeah, it does not function like a "true" keysense wire. older vw's are not the same.


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## MI_canuck (Dec 21, 1999)

*Re: (vdubnick)*

that may be the case older ones, I haven't a clue... this thread pertains to Monsons and MKIVs...


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## quality_sound (May 20, 2002)

Anyone have the wiring info for a MkV? I've been looking for this info fomr a year and a half and on a MkV the wiring at the cluster is different and runs into a dash support bar. ugh.


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## kwalton (Sep 3, 2001)

*Re: 12V switched and key sense wire (vdubnick)*


_Quote, originally posted by *vdubnick* »_
please dont tell me that that black loom in the corner by the foot rest is your power wire....

i haven't been in the car audio forum too much in the last year or so. It's funny to see that these 2 pics that i took when i first bought my old 04.5 gli are still floating around in here. 
that black loom is in fact my main power wire but rest assured it was only pre-run into the car as i was starting the system install.


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## cmondale (Aug 1, 2009)

*Re: 12V switched and key sense wire (phool27)*

Hello, I just tried the 75x connection, it is not switced to use your radio in Acc or off position. I tapped into fuse # 10 and worked perfectly as stated above. My car is a 2003 jetta 2.0. thanks to all
above for their help.


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## sappersMKIV (Dec 17, 2006)

*Re: 12V switched and key sense wire (cmondale)*

How come no one is using the radio interface? I bought one and it will be here tomorrow. Ill let you all know how it works.... http://www.amazon.com/C2R-VW-R...r=1-1


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## cmondale (Aug 1, 2009)

*Re: 12V switched and key sense wire (vdubnick)*

I quite honestly didn't know there was one lol, It costs nothing for the #10 fuse tap. not sure what the adapter adds but let us know how it works


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## sappersMKIV (Dec 17, 2006)

*Re: 12V switched and key sense wire (cmondale)*


_Quote, originally posted by *cmondale* »_I quite honestly didn't know there was one lol, It costs nothing for the #10 fuse tap. not sure what the adapter adds but let us know how it works
It works like a charm! Its a bit expensive for some of the cheap asses here that can use an alternative method. The interface has the option to still be able to use the steering wheel buttons and such. I would recommend it to anyone changing out the stock deck. Oh yea I have dimmer too... Im running an AVH P4100DVD from Pioneer.


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## jcoutur (Feb 19, 2012)

phool27 said:


> As most of you know, the Monsoon Double DIN radios obtain their switched 12V line from the CAN-BUS. When planning for a replacement HU, you will need to get your switched 12V from somewhere else in the car since it's not available at the stock wiring harness.
> One result of the Double DIN Monsoon receiving its switched power in this way, is that the radio will continue receiving power until the key is removed from the ignition. In other words, if you have the radio on and turn the car off and leave the key in the "OFF" position, the radio will remain on. It is only after you remove the key from the ignition that the radio shuts off.
> I would like to retain this feature with my new head unit. After researching this topic for a couple of days, I have found a variety of answers that don't really add up to anything conclusive when considered together. I'm hoping someone here can clarify this.
> Here's what I've heard and know to be true:
> ...


 On my 2009 jetta, the blue wire of the car ingnition cylinder is the accessory wire. Carefule if you dismantle the electronic underneath the steering and switch the car key on you will get an air bag failliure. 

Use a relay to feed your devices. 

Thanks to a friend of mine for the info.


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## kno333 (Apr 12, 2013)

*Cannot find key sense wire on A6*

Hi,
Do any of you happen to know where the key sense wire is on an Audi A6 C5 '02? Sorry to post in a largely irrelevant thread, but I am struggling to find any help elsewhere.
Thanks!


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## kwalton (Sep 3, 2001)

Red at the ignition harness.


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## szilardsajgo (Jul 21, 2013)

*Problem*

Hello,

I have a problem, i have a 2001 VW jetta, with single din stereo. I have replaced it with an OEM double din monsoon stereo.
I am getting the power from terminal 75X but every time i turn my car off and back on again, the stereo needs the safe code to be put in, i have the code it is just a pain to put it in every time. Can i bypass this step? 

Thank you.


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## ravendarat (May 24, 2013)

Your ign wires and 12 volt wires at the deck are backwards.


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## brak42o (Feb 8, 2014)

I cant see any of the pictures that are said to be posted.. I have a 2002 passat that had a double din radio that i am trying to replace however i cant get the thing to shut off. can someone please help? i understand i have to find the keysense wire? any help would be great


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