I recently attempted to install an aftermarket stereo into my 2010 HHR without the factory harness and matched the colors according to this https://www.the12volt.com/installbay/forum_posts.asp?tid=80607 but the only thing that works is the front left speaker. If you know the correct wiring please help.

 

Welcome to the site, I’m sure one of our audiophiles will chime in, I’ve only seen of trying to avoid the purchase of adapters, usually from Crutchfield.

 

You don't state which model HHR or more importantly which stock radio system you have.
Anyhow. Here's the wiring for the system without the amp. It's is a 2006 schematic but the colors should be the same for your's.

 

What did you do for switched 12V? What did you do about chimes?

Did you replace the speakers? Speakers are a known weak point.

They have the - wrong

Here is the plug side:

 

I haven't replaced the speakers yet, but all worked before I replaced this stereo. Planning on replacing the front speakers with jbls I bought. For the acessory I used the add a circuit and tapped into fuse 21. Thanks for the help, i will try these connections!

 

Note that the speakers don't have a common ground.

 

Is this a note when installing the speakers or the stereo?

 

Well if you are matching wires up like the diagram you supplied you would think that only 1 wire carries +/- or that it does not matter which is which. If you look at the wiring diagram I supplied you should notice that each speaker has a - and a +. Many amateur installers just throw all of the speakers to ground on one side and + from the radio on the other.

The wiring guide you supplied might "work" but it is misleading and could end up shorting speakers, depending on how you read it.

 

Looking back at the diagram you provided and the one that I followed, I believe wired them the same way.

So just some troubleshooting questions:
How would have I shorted the speakers?
Could that be the reason that they aren't working and my wires are correctly installed?
Would I be able to test if the speakers are blown by connecting a 9V battery to the leads?

Sorry for the many questions, it's my first time doing any of this and came in over my head but it's kinda too late now to turn back. Thanks so much for your time and responses.

 

The speakers should be 4 or 6 ohms, if I recall correctly. If they are either zero or infinite they are bad.