jgoldwood

Hello, everyone. I am wanting to replace all of the stock speakers in my 08 SS and have a few questions. My HHR came with the upgraded 7 speaker Pioneer system with amp and it is complicated the install. I am going to be using a Alpine IVA-W505 for the headunit paired with a few sets of components and one or two subs. First, with the GMOS-LAN-04, is it normal to not splice the speaker wires out of the headunit with the harness but simply use the 4 rca cables? The directions are telling me to plug the 4 rcas into the front and rear amp outputs on the headunit. I have never seen this before? How would I run a multi-channel amp for the 6 speakers other than the subs? Also, how do you use a different amp and sub? I think the factory ones are pretty weak and would like to replace them. Do you simply cut and splice wires in the back of the trunk just before the stock amp? Examples of previous installs would be great!! Thank you, all!

prod

If you are replacing the head unit and all speakers, might as well run new speaker wires too.
The metra harness is meant to take the RCAs from the head unit and plug straight into the factory wiring for the amp, which you wont be using.
When adding aftermarket amps, its simpler to just connect the headunit to the amps with RCA cables. You then chain the amps together using their RCA outputs/inputs.
Your only use for the metra harness would be to keep the door chimes and onstar, if you require them.
I also have the lan-04 but I wont be doing the head unit for a while, so I cant give any more details than that, sorry. I would test the outputs of the metra harness and make sure they are within the limits of whatever amps you will be running. If they are, then just wire them to RCA plugs and plug in your amps.

jgoldwood

Thanks for the reply. I actually am wondering if I got a "dead" harness as I purchased it used. I cannot get my headunit to power up. Also, because you have the LAN-04, you've seen how the speaker cables out of the harness have been combined to make 4 rca cables? The directions say to plug those into the aftermarkets stereo's front and rear amp outputs. Are you saying if I'm going to use an amp to power the door speakers to simply cut off the rcas and splice the speaker wires? I still don't understand why I do not have power. The black/yellow wire is simply for adjusting the OnStar and chime volume, and doesn't have to be continuously grounded, right? Also, I'm using a Pac-TR7 which might be causing some troubles.

prod

Not sure why your head unit isnt working, sorry, if its wired up completely and correctly with the harness it could be bad.
As for the RCA connectors, no, those RCAs are the inputs from the head unit and should be kept. Connect the harness to the head unit per the instructions.
Its the vehicle side you need to modify, the big black connector, as you no longer want to use the factory amp.
Note, I have not tried this as I dont have a head unit yet, so I would get more input from others before trying it. Its possible there could be some kind of feedback signal from the factory amp needed to operate the system, but Im hoping thats not the case.
It sounds like you want to replace the factory amp with aftermarket ones.
You need to cut the audio output signal lines to the factory amp and solder RCAs onto them, then connect them to aftermarket amp inputs. Here are the diagrams for the vehicle harness.


So it looks like you would do this:
Connect C1 wires 5 (+) and 4 (-) to an RCA plug, this is your right front.
Connect C1 wires 7 (+) and 6 (-) to an RCA plug, this is your left front.
Connect C2 wires 4 (+) and 5 (-) to an RCA plug, this is your right rear.
Connect C2 wires 6 (+) and 7 (-) to an RCA plug, this is your left rear.
I think positves are usually connected to the center electrode of the RCA plug while the negatives are connected to the sheath. All of those would be connected to the 4 channels of an amplifier.