Just wanted to say thanks for the detailed instructions. Just went through the full install on my 2008 HHR SS, and could not have done it without this post. Seems that quite a few folks still don't understand that just because you CAN use high level inputs, does not mean you should. Why spend the money on a nice aftermarket amp just to have the signal get run through the old amp, and then essentially "downconverted" again? Every time you process the signal, there are slight distortions and noise introduced, that is the whole point of tapping in to low level. If you are satisfied with using the speaker level inputs, great, and simple, just understand you are losing something in quality.

 

would anyone know where to find the wiring diagram for the hhr for the radio. i need it so that i can hook up my amp and subs in my car.

 

For the ones like me that don't want to cut into the factory speaker wires this is what I found so I can keep everything the same in my 06 LT2 and add a amp and two subs...hope it helps
http://www.autosoundcentral.com/PAC_...oemgm1416a.htm

 

To simplify tapping into the low-level wires leading into the oem amp:

If you have some of the "twisted-pair" type RCA cables laying around, you can cut them open and they end up looking exactly like the JL Audio ones mentioned on pg 2 ( http://www.crutchfield.com/p_136CLR2...W.html?tp=2610 )...

Once you cut them open, you'll find separately-insulated +ve and -ve wires, just like a speaker cable. No messing with the coaxially-configured wires as described in the first post.

Hopefully this saves someone some time, and potentially a few bucks...

Happy installing!

 

did you get that to work?

 

can anyone confirm if that works?

 

can anyone tell me if the original post is accurate for an 09 ss with the amp/sub in the back it sounds like it is just trying to get some insight before i go of cutting and splicing on a new car

 

i dont know if the first post is accurate but i can't make it to work!! Those low level line inputs going into the factory amp, have 6 volts+ all of them!!!WTHeck!!! I have a nasty pitch sound when i turn on
the car!! And i cant use those wires that supossed to be - ( neg speaker input) it has 6 volts!!! ..... Im i missing something????

 

me too... same thing.. I started a new thread..... HELP cant stand having my HHR tore up with all the panels out..

 

If you add Aftermaket amps without completely bypassing the stock amp, you will get a really atomic (not good ) noise from your speakers. The Stock amp has two parts, Bass and all the rest. cut the input (for which ever you are working with) run it to your new amp. Then connect the output from your amp to the speaker wires going back to the stock wiring harnes. The stock amp will have no function then unless you just did the bass. But go ahead an upgrade the doors, amp them too. YOU DID REPLACE YOUR DOOR SPEAKEKS DIDN"T YOU??? FAR OUT! 900 watts RMS at the sub an 80 watts RMS @ the doors is FAR OUT. Check out my install in my gallery. door amp on the left, sub amp on the right.