Key Off Radio Power

[JoshMcMadMac]

How does the stereo get 12V after you turn the key off, prior to opening the door? I probed the power lines, and it seems that there is on 12V source for starting, one 12V source for the run/accessory position, and the constant 12V. Where is the delayed-off 12V coming from?

I would like to wire my satellite radio in to get power when the stereo does; any suggestions?

 

[joegr]

How does the stereo get 12V after you turn the key off, prior to opening the door? I probed the power lines, and it seems that there is on 12V source for starting, one 12V source for the run/accessory position, and the constant 12V. Where is the delayed-off 12V coming from?

I would like to wire my satellite radio in to get power when the stereo does; any suggestions?

The radio always gets all its power from the constant 12V source. The run/accessory wire just tells it when to turn on. The 12V start wire mutes the radio and shuts the display off while the starter is engaged.

Internally, the radio (unless you have navigation) does the delayed turn off.
Fortunately, all if not lost for you. The power windows also have a delayed turn off circuit. You could tap your satellite radio power from there. You can find the correct wire in the driver's door, or behind the trim on the passenger side of the rear package tray (where the cabling runs to the moonroof). I don't have my wiring diagrams with me to give you the wire color.

 

[JoshMcMadMac]

The radio always gets all its power from the constant 12V source. The run/accessory wire just tells it when to turn on. The 12V start wire mutes the radio and shuts the display off while the starter is engaged.

Internally, the radio (unless you have navigation) does the delayed turn off.
Fortunately, all if not lost for you. The power windows also have a delayed turn off circuit. You could tap your satellite radio power from there. You can find the correct wire in the driver's door, or behind the trim on the passenger side of the rear package tray (where the cabling runs to the moonroof). I don't have my wiring diagrams with me to give you the wire color.

Great information, thank you. How much digging does it take to get to the power window wires from the stereo? Is there an easy way to get the wire color/information for a 2005?

 

[djknowledge]

why do you want to change it, is it draining ur battery? when you open the doors to leave after the key is off does it shut off or???

 

[joegr]

why do you want to change it, is it draining ur battery? when you open the doors to leave after the key is off does it shut off or???

He's adding a satellite receiver. He wants it to stay on after turning the key off, like the radio does, until he opens the door.

 

[joegr]

Great information, thank you. How much digging does it take to get to the power window wires from the stereo? Is there an easy way to get the wire color/information for a 2005?

I can get you the color info tonight. If you do some searching, I have posted it here before, but I don't recall which thread(s).
The wire in the door is difficult because you would have to feed a wire from the door to the dash. Of course, the wire in the door already runs under the dash, but I couldn't find/identify it there. It was easier for me to splice to the moonroof wire at the rear deck.

 

[joegr]

I can get you the color info tonight. If you do some searching, I have posted it here before, but I don't recall which thread(s).
The wire in the door is difficult because you would have to feed a wire from the door to the dash. Of course, the wire in the door already runs under the dash, but I couldn't find/identify it there. It was easier for me to splice to the moonroof wire at the rear deck.

Okay, I found the other post. Here it is.

The wire color is gray with a violet stripe. I tapped it at connector C501, which is to the driver's door module. It also runs to the passenger side power window motor, at connector C608. It runs through connectors C610 and C511 to get there. Unfortunately, those are both in the doors too. It does cross from the drivers door to the passenger door, but I can't find any connectors under the dash for it. It also connects to the navigation system (if you have it) at C4209 as a gray with black stripe wire and at C212 as a gray with orange stripe wire. It connects to the moon roof motor via C920 still as a gray/violet wire. There is also a connector it passes through under the rear package shelf.

My guess is your best bet to find it will be behind the left or right kick panel in the front of the car. Be warned that there may be other wires with the same colors that do something else, so test whatever wire you do find.

 

[Alax7]

Great information, thank you. How much digging does it take to get to the power window wires from the stereo? Is there an easy way to get the wire color/information for a 2005?

Not very hard. 6 screws to take the door panel off and just PULL of the pannel. Find the right wire and run wires either under the carpet to the center console to the back of the stereo or from the door to under the glove compartment, might be able to get squeeze the wire to the stereo from under thg glove box.

 

[JoshMcMadMac]

Okay, I found the other post. Here it is.

The wire color is gray with a violet stripe. I tapped it at connector C501, which is to the driver's door module. It also runs to the passenger side power window motor, at connector C608. It runs through connectors C610 and C511 to get there. Unfortunately, those are both in the doors too. It does cross from the drivers door to the passenger door, but I can't find any connectors under the dash for it. It also connects to the navigation system (if you have it) at C4209 as a gray with black stripe wire and at C212 as a gray with orange stripe wire. It connects to the moon roof motor via C920 still as a gray/violet wire. There is also a connector it passes through under the rear package shelf.

My guess is your best bet to find it will be behind the left or right kick panel in the front of the car. Be warned that there may be other wires with the same colors that do something else, so test whatever wire you do find.

Awesome, thanks! It is a pain to have to dig through the door to get to it, but I will be in there for a set of speakers soon anyway.

What sucks is that I have the perfect power source with the "SAT" button converter...but for some reason it comes out with 11.3V, which is not enough to drive the radio.

 

[LS4me]

I used a (IIRC) line converter on one of the speaker wires. This device bumps up the voltage to 12V and will connect to the power wire of the satellite receiver. I will keep searching for how I did it.

Something like this.

 

[JoshMcMadMac]

I used a (IIRC) line converter on one of the speaker wires. This device bumps up the voltage to 12V and will connect to the power wire of the satellite receiver. I will keep searching for how I did it.

Something like this.

That looks interesting. I am assuming it is basically a fancy relay? It says it has four wires; ground, 12V, signal, ?

 

[LS4me]

That looks interesting. I am assuming it is basically a fancy relay? It says it has four wires; ground, 12V, signal, ?

What it does is bump up the voltage in the speaker wire to 12V so you can power a 12V device, such as the satellite receiver. The one I have is from from Directed Electronics.

 

[1LoudLS]

That looks interesting. I am assuming it is basically a fancy relay? It says it has four wires; ground, 12V, signal, ?

no just a relay, but it reads the databus signals (CAN) and will turn off and on from the signals that the cars computer sends to the radio. so it gets 12v constant in, ground, databus in, and ACC out. the databus wire is the line that all of the cars systems "talk" to each other on, and with the GM's can either be found at the radio harness or the diagnostic connector under the dash

i'm assuming that the databus signals have to be different between a GM and the Ford system, right?

do they make something like this for Ford? i did notice that most (if not all) of the new fords no longer have a ACC wire at the radio harness (just like GM and
Chrysler did a few years ago)

 

[JoshMcMadMac]

What it does is bump up the voltage in the speaker wire to 12V so you can power a 12V device, such as the satellite receiver. The one I have is from from Directed Electronics.

It cannot "bump up" to 12V without a 12V source, though. There are a couple of 5V signal wires off of the back of the stereo, too. I will look into it, thanks.

 

[joegr]

What it does is bump up the voltage in the speaker wire to 12V so you can power a 12V device, such as the satellite receiver. The one I have is from from Directed Electronics.

If you are talking about
http://www.discountcarstereo.com/detail.aspx?ID=1349
then that is not what it does at all.

It listens to the vehicle communications bus (via it CAN or something else) and turns on the 12V power output based on the commands that it sees on the bus. It listens for the accessory on command and turns the output on. Then, when it gets the accessory off command, it waits twenty minutes or until a door open command is received (whichever happens first) and then turns the power off. This is the same thing that the radio does internally.

Unfortunately, the linked one is for GM. AFAIK, no one as ever done one for the LS.

 

[joegr]

no just a relay, but it reads the databus signals (CAN) and will turn off and on from the signals that the cars computer sends to the radio. so it gets 12v constant in, ground, databus in, and ACC out. the databus wire is the line that all of the cars systems "talk" to each other on, and with the GM's can either be found at the radio harness or the diagnostic connector under the dash

i'm assuming that the databus signals have to be different between a GM and the Ford system, right?

do they make something like this for Ford? i did notice that most (if not all) of the new fords no longer have a ACC wire at the radio harness (just like GM and
Chrysler did a few years ago)

Similar modules are available for most Ford/Lincoln/Mercury. However, it seems that the LS is unique enough that none of these work with it, and they weren't enough of the LS made for someone to offer a specific module for it, that I know of.

 

[joegr]

It cannot "bump up" to 12V without a 12V source, though. There are a couple of 5V signal wires off of the back of the stereo, too. I will look into it, thanks.

You are certainly correct about the device in question.

However, just for the record...

It is possible to "bump" 5V up to 12V. The circuit required is called a switching boost regulator circuit (there are other ways too, but this is the most popular).
They aren't magic, the power out still has to be less than the power in. If you need 1A out at 12V, and your boost circuit is 80% efficient, then you will need 3A in at 5V.

This doesn't help here because there aren't any 5V level lines that do what you want anyway. If there were, it would be simpler to just use a relay.

 

[1LoudLS]

It cannot "bump up" to 12V without a 12V source, though. There are a couple of 5V signal wires off of the back of the stereo, too. I will look into it, thanks.

they do make line output converters that do need constant power and ground and then they just "look" for any signal on the speaker wires. when they "see" something there they send out a 12v turn on signal.

i'm assuming this is what he is talking about.

 

[JoshMcMadMac]

This doesn't help here because there aren't any 5V level lines that do what you want anyway. If there were, it would be simpler to just use a relay.

Do you know of a relay that will switch from an 11V source and handle 12-14V through?

 

[joegr]

they do make line output converters that do need constant power and ground and then they just "look" for any signal on the speaker wires. when they "see" something there they send out a 12v turn on signal.

i'm assuming this is what he is talking about.

Yes, they do, but that's not what he linked to.

 

[LS4me]

they do make line output converters that do need constant power and ground and then they just "look" for any signal on the speaker wires. when they "see" something there they send out a 12v turn on signal.

i'm assuming this is what he is talking about.

Yes, that is what I mean, I just don't remember what it's called.

You should be able to talk to a car audio installer, describe what you want to do (let them know that the radio controls the delay) and they should know the relay you need. I am pretty sure Directed Electronics makes the unit I used. It is small, about the size of a couple packs of gum.

Like this without the RCA outputs.



SUCCESS!!! This is very similar to what I used. The green wire would piggy-back off the speaker wire and the blue to the satellite receiver.

 

[joegr]

Do you know of a relay that will switch from an 11V source and handle 12-14V through?

If the 11V source is constant, and can supply 100mA or so, then just about any 12V relay would work with it. (The coils normally pull in at about 9V.)

 

[1LoudLS]

Like this without the RCA outputs.

that was exactly what i was talking about.