Well that'll make the difference,a big difference.

 

Any advice from here? Cd player powers up and looks like its running fine i just have no sound. Also all my gauges have stopped working on my dash

 

You'll need to confirm that you have the correct adaptor for your set up. Then a battery lobotomy to reset the computers

 

X2 to Oldblue's advice, and the non-presence of OnStar could mean your HHR is an ex "Fleet Vehicle". But to see exactly what audio system options you have, find the build tag on the inside of your glovebox, it's a 2" x 3" white or silver label covered with a list of three digit codes.

Here are the Audio RPO Codes...

UE0 Communication System - Vehicle, G.P.S. - Not Installed

UE1 Communication System - Vehicle, G.P.S. 1

UQ3 Speaker System - Enhanced Audio

US8 Radio - AM/FM Stereo, Seek/Scan, CD, Auto Tone, Clock, ETR, MP3, RDS

US9 Radio - AM/FM Stereo, Seek/Scan, RDS, Multiple Compact Disc, Auto Tone Control, Clock, ETR, MP3

UW5 Speaker System - 6, Base

U1C Radio - AM/FM Stereo, Seek/Scan, CD, Clock, ETR

U2K Digital Audio System - S-Band

It's your HHR's Birth Certificate, every option and optional variation has a code.

 

GM integrated a data bus system with the factory radio as a relay/hub or something like this starting around 2004. It apparently saved GM $$, but makes life more difficult for people trying to replace radios. I didn't get all the details, but basically without the factory radio installed, I wouldn't get indicator warning beeps for some sensors like if you leave the keys in the ignition, if you leave the lights on, if you don't put on your seatbelt, etc. The two options were to either run a power line for the ignition power to a spare fuse in the fuse box, or buy this fancy harness that had some little black box/circuit board thingy that replaces what you lost with the factory stereo. This is what I had to do in my GMC Savana, and it worked perfectly. Paid about $85 online

 

 

Welcome to the site, that's what is required to adapt an aftermarket radio to our little Trucklets. And many other cars out there!

 

here's a link for the harness I used. Obviously you won't need the mounting hardware as this was for my Express, but this is the harness needed.

Chevy Express 2008-2012 Double DIN Stereo Harness Radio Install Dash Kit Package - SC2-RadioKit206