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Aftermarket radio install: where to tap in for ignition on?

Dialn911

Full Member
Joined
Dec 28, 2011
Messages
112
Hey guys, I'm installing a double din head unit in my 2003 Chevy avalanche. I am having difficulty finding what color wire on the stock radio harness is used for Ignition on to power the radio on and off.

There are too many things tapped into the Ignition harness under the steering wheel, and im afraid this head unit is going to put too much demand on the system to tap into the Ignition wiring.
I'm having a hell of a time finding what core wire is used as an Ignition on and off wire in the harness where the 4adio plugs in.

Can anyone tell me what they used?
 
You aren't going to find one. The "ignition" wire doesn't exist in the stock harness, the factory HU is commanded via the data bus.
If you do not want to run an RAP/Ignition signal from an alternate location you need to purchase the proper adapter from somewhere like https://pac-audio.com. Crutchfield.com or calling Crutchfield will be the fastest way to determine exactly which one(s) you need.

 
As Calicak89 mentioned you will NOT find an ignition lead. It is totally done by the datastream.

Hopefully you didn't chop up the factory harness to do this as it is much easier to purchase the proper harness and just plug it in.

There are two ways to accomplish this.

The proper Pac adapter as already mentioned. This will bring you the Chime, RAP (Retained Accessory Power. Used instead of ignition.) and can bring steering wheel or rear audio controls to your new radio if so equipped and the radio supports it.

The OTHER way to do this is to tie into the Sunroof relay. If your truck has a Sunroof the sunroof is powered on with a RAP signal directly from the BCM. My truck does not have a sunroof so I wired a relay into the wire that comes from the BCM for this. The BCM is the negative trigger so you need to install a relay with the positive going to a constant positive source and the negative going to the BCM pin for the sunroof. I think I spelled out which pin this is in my "knightrider" thread. If your truck does have a sunroof you should be able to find the relay mounted behind the glove compartment connected to the A-Pillar. It MAY even be in the Right hand "fuse panel" but the factory manual seems to show it mounted behind it possibly at the fire wall.

You COULD tie into the ignition switch for it and your radio should be using the constant +12 volt line for its supply power anyhow. The ignition lead should just be a trigger to turn it on and off...
 
What headunit are you putting in ???
 
I should also mention that be very careful when tying into the BCM. I put a .25 amp fast blow fuse inline with it just in case but you can toast your BCM if you are not careful.

Rodney
 
My truck doesn't have a sunroof.

As far as adapter,  I thought I had purchased the chimes adapter.

After you guys reminded me of the chimes adapter, I started looking through all the gear I got, and now I realize I purchased a regular standard adapter for an aftermarket install, I didn't buy the one with the chimes like I had thought I did.

It sounds like what you guys are saying, the adapter with the chimes will plug into to the stereo harness and retain the accessory on feature, and then my understanding is you spice tge speaker wire from the radio into the adapter for the chimes audio, and then the RCA is used for the audio.
 
Almost...

The after market harness with Chime will give you all the proper wiring. The Chime will be a speaker in the adapter. Any I have used have been this style anyhow.

If you have the BOSE system you will have to bypass the amplifier which should be somewhat easy. The harness you get may include the bypass in it if you get the right one.

Here spending an extra $10-20 for the right harness will save you a lot of work.

If you are using after market amplifiers, running RCA's from the stereo and running new wire to the speakers you will not need to worry about the BOSE amplifier.
 
I should clarify, the audio is going from the head unit to two AMPS via RCA. The speaker wire in the harness that plugs into the stereo will be spliced to the chimes adapter, giving the speaker in the module audio input for the chimes.

I'm just planning on bypassing the BOSE amp by tapping into the factory speaker wire into the harness that's already running to speakers. I tapped into the rear speakers this way when installing subs and an amp using the factory head unit.

Seems like a lot of unnecessary work to run new wires to the speakers when they can be tapped easily like was done with  my subs.

Unfortunately, it looks like the chime adapter I got from Crux was defective. I have to order another. I hooked it up to the harness as directed, this has a plugin for both BOSE amplified and non-BOSE systems. It is part number SOCGM-17C

When I plugged it in, it would chime twice then die. NOthing after that. There was a little blue LED light on inside, but that's it. It would not continue to chime, and would not send any power through the accessory on wire for the stereo.

the wiring was good, the ground was good, I checked the constant 12 volt power with a voltmeter going to the adapter and that was good as well. It would not send any signal to the stereo to turn on. The only way to get a response was to unplug it doing a hard reset, and then plug it back in. Everytime this was done, it would chime twice and then nothing.

I called Crux on the phone and they said it should be working, and to return it and get another.

Does anyone here have the color codes for the speaker wires in the Bose amp harness?
 
http://www.chevyavalanchefanclub.com/cafcna/index.php?topic=80500.0
 
thank you for the link.

DOes anyone know what the small square harness that plugs into the back of the stock head unit is for? if you're looking at the stereo head on, on the left side of the back of the stereo,  there is the main harness. On the right side, there is a square smaller harness. I can't figure out what this for or what it does?

the chimes harness doesn't use it, nor does anything else. Anyone know?

Also, I have never installed steering wheel control adapters before, anyone know where the steering wheel controls plug into? does it plug into the back of the aftermarket stereo?
thanks
 
I believe that's the entertainment Bus, for OnStar, XM radio, an external CD player inputs.

http://www.chevyavalanchefanclub.com/cafcna/index.php?topic=44768.msg707821#msg707821
 
Byron is correct. It is the connection for the XM radio module which is behind your glove box. Should be 4 wires coming from it.

As to the steering wheel controls, your radio has to support them for them to work. If your radio supports them it should be a very simple connection. If it doesn't then they won't work.
 
Thank guys,
I didn't realize my truck had a connection for XM radio. Didn't know 03's had this. There is a connection behind th glove box you say?

I was confused because when I unplugged it, it didn't seem to effect anything at all.

BTW...what should I look for in the glove box to tell what my system is? can anyone explain to me the significance of UQ7 and Y91? etc.....?

thank you for the info on the SWC. My stereo does support steering wheel controls, so I should be good there. JUst wasn't sure.

I just realized, I have ESI on my laptop, and all the wiring should be in there. Still would have to track it down though, its in odd places sometimes.

 
The codes listed in your glove box can easily be looked up online... There is more than one outright list of them online as well.

Listed as Build Codes or option codes.
 
To decipher the RPO codes in your glove box read this thread:

http://www.chevyavalanchefanclub.com/cafcna/index.php?topic=84494.0
 
Glove box decal lists RPO codes.
See here:
http://www.chevyavalanchefanclub.com/cafcna/index.php?topic=84494.0
 
Thanks guys.

Anyone familiar with the Crux SOCGM-17C?
I got it hooked up and wired to the door speakers, the new one chimes this time as it should, and powers on the radio. However,  there is zero audio coming from the door speakers when hooked up to the harness.

Im not going to run it this way, I am going to use RCA out to an amp for components, but it bothers me I'm not getting any audio through the standard speaker wires.

as far as I know, it should have sound going to the door speakers once soldered up, for installs that ONLY want to replace the stereo and keep the BOSE system.

I am confused as to why I m not getting any audio.

Any ideas? 

 
So if all you wanted to do is add subwoofer amps. You weren't very clear in the first post.
 
If you have everything hooked up and are getting sound from the front speakers and not the rears I suggest you check out the speakers...

In my truck the rears were toast and apparently had not been working for a long time but I didn't notice since the fronts were still working fine.

The other option is if you have the Rear Seat Audio then you need to bypass the Rear Seat Audio to get the rear speakers.

To Bypass the RSA you will find a total of 4 pairs of twisted wires. Match up the wires of the same colors and connect them. You will find that these wires are the audio into the RSA and out of it. The RSA uses the rear channels of the OEM radio to provide audio to the module. When the module is in use the rear speakers are shut off. The rest of the wires provide power and datasignals to the module and can be ignored. Without the factory radio in place the default mode for the RSA module is to NOT pass the speaker signal through. This is assuming your using the BOSE amplifier to run your rear speakers. (The BOSE amplifier has a remote turn on just like any other amplifier. Different in Cadillacs)
 
MS03 2500 said:
So if all you wanted to do is add subwoofer amps. You weren't very clear in the first post.

No,
That not all I'm doing. Please re-read my post.

 
redheadedrod said:
If you have everything hooked up and are getting sound from the front speakers and not the rears I suggest you check out the speakers...

In my truck the rears were toast and apparently had not been working for a long time but I didn't notice since the fronts were still working fine.

The other option is if you have the Rear Seat Audio then you need to bypass the Rear Seat Audio to get the rear speakers.

To Bypass the RSA you will find a total of 4 pairs of twisted wires. Match up the wires of the same colors and connect them. You will find that these wires are the audio into the RSA and out of it. The RSA uses the rear channels of the OEM radio to provide audio to the module. When the module is in use the rear speakers are shut off. The rest of the wires provide power and datasignals to the module and can be ignored. Without the factory radio in place the default mode for the RSA module is to NOT pass the speaker signal through. This is assuming your using the BOSE amplifier to run your rear speakers. (The BOSE amplifier has a remote turn on just like any other amplifier. Different in Cadillacs)

I'm getting no sound from the speakers at all. I know they work, they worked fine with the stock unit. The new unit hooked up to the adapter, no sound.

The only way I can get sound is through th he RCA out.
 
Just to be clear.

I am NOT using anything from the bose system.  I am bypassing the whole thing.

New head unit, new components in the doors, new subwoofers, and two amps, one for the subs, one for the doors.

For some reason though....with the new stereo simply hooked up using the chimes harness, and not bypassing anything yet, I'm getting no audio through the speakers using the normal method on bose settings with the chimes module.

It's odd.

I'm AM NOT planning on using it this way, but it bothers me it's not working like it seems it should in that ser up.

I plan on using RCA out for the subs and door speakersto the amps, and then tapping into the speaker wires for the doors. The sub get a direct connection.
 
Nvm....

A tech called me back and stated that there are a few rare set ups in the Bose systems where the data is not matched with the module I have. They said since I'm running RCAs, I'll be fine. If I was going to try to use the stock system, there is a different module they recommend over the one I have.
According to the tech, 1 in 13 AVYs will run into the problem I just experienced.

Lucky me...I should go buy a Powerball ticket. 
 
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