12V constant wire question

xaiolin · 06-14-2009, 12:21 AM

I bought a 12v test light and found out that I have two 12v constant wires and one 12v switched. One 12v constant is red/green and the other is
white/red/yellow.... the 12v switched is purple/white. Does anyone know which is the "true constant" that I should be connecting my radio positive wire to? Also, why are there two?

jay2001 · 06-14-2009, 01:09 AM

Please say that you did not use one of those light bulb test wands to the White/Red/Yellow lead? This is a data line and not suppose to ever see a low impedance load. I hope that everything is okay after you put things back together. In the high technology age we are in, Please use a high imedance tester like a DVM and throw that wand away before you trigger an air bag.
The constant +12 is the Red/Green.

GTUnit · 06-14-2009, 01:11 AM

^ good advice right there

xaiolin · 06-14-2009, 08:33 AM

Quote:

Originally Posted by jay2001

Please say that you did not use one of those light bulb test wands to the White/Red/Yellow lead? This is a data line and not suppose to ever see a low impedance load. I hope that everything is okay after you put things back together. In the high technology age we are in, Please use a high imedance tester like a DVM and throw that wand away before you trigger an air bag.
The constant +12 is the Red/Green.

thanks

packrat555 · 06-14-2009, 12:27 PM

he is referring to the ibus line

xaiolin · 06-14-2009, 01:24 PM

Quote:

Originally Posted by packrat555

he is referring to the ibus line

thanks, i appreciate this

xaiolin · 06-14-2009, 02:55 PM

Quote:

Originally Posted by packrat555

he is referring to the ibus line

Do you know what these do:

I-Bus
12v Acc
12v Ilum
12v Ant out
Phone Mute

packrat555 · 06-14-2009, 11:36 PM

I-Bus is the data link for the car don;t touch that unless you re hooking some kind of ipod interface and they instruct you
12V ACC is the 12V that is switched on with the ignition
12V Ilum is the voltage to the radio display light, used so that it will be controlled by the dimmer like the rest of your gauges
12V Ant Out is used to control a power antenna (I think)
Phone Mute somehow works with the bluetooth kit. There is a corresponding button on the steering wheel, I wish there was a way for it to simply must the radio when pressed but I don;t think anything like that is possible.

xaiolin · 06-15-2009, 07:11 PM

Quote:

Originally Posted by packrat555

I-Bus is the data link for the car don;t touch that unless you re hooking some kind of ipod interface and they instruct you
12V ACC is the 12V that is switched on with the ignition
12V Ilum is the voltage to the radio display light, used so that it will be controlled by the dimmer like the rest of your gauges
12V Ant Out is used to control a power antenna (I think)
Phone Mute somehow works with the bluetooth kit. There is a corresponding button on the steering wheel, I wish there was a way for it to simply must the radio when pressed but I don;t think anything like that is possible.

thanks man... im trying to figure out why my cd player and aux arent working but the radio is

06-14-2009, 12:21 AM	#1
xaiolin Registered User Join Date: Mar 2009 Location: VA Beach Posts: 33 My Ride: 2001 BMW 330ci View My Garage	12V constant wire question I bought a 12v test light and found out that I have two 12v constant wires and one 12v switched. One 12v constant is red/green and the other is white/red/yellow.... the 12v switched is purple/white. Does anyone know which is the "true constant" that I should be connecting my radio positive wire to? Also, why are there two?

06-14-2009, 01:11 AM	#3
GTUnit Registered User Join Date: Feb 2008 Location: SoCal Posts: 349 My Ride: short bus View My Garage	^ good advice right there __________________

06-14-2009, 12:27 PM	#5
packrat555 Registered User Join Date: May 2009 Location: Texas Posts: 496 My Ride: 2001 325i View My Garage	he is referring to the ibus line Attached Thumbnails

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06-14-2009, 01:09 AM	#2
jay2001 Registered User Join Date: Jul 2007 Location: SJ CA Posts: 82 My Ride: 325i & 530i View My Garage	Please say that you did not use one of those light bulb test wands to the White/Red/Yellow lead? This is a data line and not suppose to ever see a low impedance load. I hope that everything is okay after you put things back together. In the high technology age we are in, Please use a high imedance tester like a DVM and throw that wand away before you trigger an air bag. The constant +12 is the Red/Green.

06-14-2009, 11:36 PM	#8
packrat555 Registered User Join Date: May 2009 Location: Texas Posts: 496 My Ride: 2001 325i View My Garage	I-Bus is the data link for the car don;t touch that unless you re hooking some kind of ipod interface and they instruct you 12V ACC is the 12V that is switched on with the ignition 12V Ilum is the voltage to the radio display light, used so that it will be controlled by the dimmer like the rest of your gauges 12V Ant Out is used to control a power antenna (I think) Phone Mute somehow works with the bluetooth kit. There is a corresponding button on the steering wheel, I wish there was a way for it to simply must the radio when pressed but I don;t think anything like that is possible.