to power the stock antenna amp with an aftermarket radio should be fairly easy. almost all aftermarket radios have a switched power output wire. this wire is used to trigger a power antenna, or to trigger aftermarket amplifiers. The wire is usually dark blue( check the wiring diagram that came with the radio). There should be enough current available from this wire to power the stock antenna amp. connect the "blue wire" to the stock antenna's power wire (pink as stated in the rest of this thread) and your antenna should work.

I hope someone is still 'out there' because I, too, have this problem and a question...
I am in the same situation as the originator (yellowjacket) of this topic, having just bought a used 2009 HHR LS. It has the stock AM/FM/CD radio. The FM band receives one very local station; the AM band receives nothing; the CD player works fine. I have followed the postings here and understand about the pre-amp (or booster) behind the headliner. I started to investigate that yesterday - removed the visors, but stopped when it bacame apparent I had to remove the A-post covers with the prominent warning of AIR BAG. I was able to pull the headliner down far enough to see a small white plastic box essentially under the antenna mount on the roof, but not far enough to actually access it to work on it. (I am assuming the white plastic box is the amplifier.) So on to my question: Can a substitute amp be placed closer to the radio? The salesman who sold me the car is trying to work with me to solve the problem in a cost-effetive manner, and wants to take it to a local guy who will try installing a new amplifier near the radio. I guess in the big picture I don't care as long as it works, but I don't want to waste a lot of time chasing rainbows, either. Does anyone have any experience with, or comments on this solution? Thanks.

Well herb. You never followed up on your other post about the antenna problem. If you want help, you should at least do a follow up on that so we know exactly where you're at in trying to find a fix.
Breaking off with 2 seperate posts about the same problem gets a little confusing.

AIRBAG is not a warning, it is a statement of fact. You will also have to remove the rear quarters to get the headliner out. The light fixtures are held to the roof by magnets.

You can see good diagrams at GM online parts stores.

If airbags scare you you can disconnect the battery, wait 15 minutes for the capacitors in the control module to discharge. The airbags will then be rendered harmless to work on and around.

I think someone may have already said this in one of these antenna threads but disconnecting the connection behind the front passenger kick panel is what worked for me. It is the one that comes down with the antenna coax, it has just one red wire in it.

From what I can tell, it powers the built in antenna booster.

Evidently, the antenna works fine without the booster, in fact, once the booster goes bad, it works better without it.

Hi Everyone,
I'm new here and came across this post and may need it brought back to life. I recently replaced the factory radio (basic audio system, no amp) in my 06 with a new head unit. I'm having the same reception issues, kind of ok on FM but could be better, and absolutely nothing but static on AM. I know for a fact that I did not connect the power antenna wire on the new radio to anything because I was thinking that was for a powered up and down antenna, but then I saw the info on the amplified/boosted antenna on the HHR and the pink wire. My question is where is the 12 volt pink wire that the radio's power antenna wire should be connected to located in the car. I don't recall seeing it. Is it part of the factory harness?

Thanks in advance. Hoping it's a simple fix!

It should be still up under the headliner at the antenna base.

According to the wiring schematic the pink wire carries a "radio on signal", so my guess is it would be the same as a "mast up/down signal".

You should probe it with a VOM.

Oh, you are looking for the radio end of the pink wire?
That runs up the passenger side A frame right next to the coax, it is probably in the big plug that you disconnected to get to the speaker and power wires. Not he speaker connector the other one with power.

Thanks donbrew, yes, I was looking for the radio end of the pink wire so I can attach the new head unit's power antenna wire to the pink wire. Glad to hear that it's on the plug, that will make it easy to find.
Thanks again for the help, that's exactly what I was looking for.

My antenna amp quit working, no stations came in unless very near towers. Removed right kick panel, cut pink wire. All stations come in great.

I had the same problem of the antenna amp no longer working. Couldn't get FM or AM stations at all. Cut the pink wire behind front passenger kick panel and now all of my FM stations come in loud and clear. Little to no AM reception. This will get me bye until I can replace the offending part, either the amp or the whole antenna if its one and the same. Thanks for the info guys! It was getting boring listening to the same CD's all the time.