Now, I'm not sure if it's just my car('07 LS, no OnStar), or my HU(Pioneer P7000BT), but I had a problem I just couldn't figure out, but believe I have...

After I installed my new stereo, my FM reception was noticeably diminished and my AM was inaudible. I am a big AM radio fan, especially in Philadelphia(610 WIP). I couldn't hear anything. It was frustrating. I had the correct antenna adapter and everything.

I was told everything-- from the HHR's radio reception is THAT bad(which isn't true, because I got excellent reception with stock HU), to the way the wiring in the car is run is the cause(BS). I was even told that the antenna adapter for the Chryslers(the one we have to use in HHR) was reversing the shield and lead, thusly grounding itself out, causing terrible reception. Well, none of the above are true.

I'm not sure about this, so it's a partial question, but do the non-OnStar HHRs still have the OnStar wiring running through the car? Meaning, is there a relay somewhere on the antenna from roof to back of radio that trips the radio antenna on when stock radio is in? Because I multimeter-ed the antenna on the roof to the antenna lead behind the HU and there was nothing. The antenna on the roof is basically useless with my Pionner HU. That's why I'm asking about a relay. Because if there is one, how do I get the connection to bridge with an aftermarket stereo? Or do I just have to run a separate antenna directly from the back of HU? Because essentially, the 'antenna' I am getting use of for my HU is the adapter from back of radio to that relay.. so I get an antenna that runs right into the wiring of the heart of the car and it doesn't even reach antenna on top of car. No wonder it's so fuzzy.

Anyway, this flustered me for about a year now, and I hope to diminish some other people's anguish. Possibly the same is Cobalt's too, I'd suppose.

 

I have no problem with my aftermarket radio install. I have an '06 LS.

Must be a bad antenna wire. My Envoy has XM and it's a different antenna and I think if you have Onstar it's a different one too.

If you have all options you'll have 3 different antennas (I think, please correct me if I'm wrong.)

*Edit*: Just looked at one site and it said that XM and Onstar can use the same antenna. But your radio antenna will be seperate.

 

my XM reception is HORRIBLE, sometimes I drive under a limb from a tree across the road and a get a couple seconds of fuzz. It embarrasing. Ya I got XM lets check it out,....OH I have to wait until this kid moves his kite so I can get a signal

 

There is no Onstar antenna relay and if you don't have Onstar or XM those cables will also not be present.

 

The HHR antenna is powered normally. I had the same problem, got better reception with it disconected. There is a harness somewhere, or so I've been told by a shop that was wrong about a lot of other stuff!

 

Are you saying that the RADIO antenna is powered?? 12vdc power to some sort of amp before the radio (head unit)??

 

who?

 

Mike?

 

You have a bad antenna adapter. Get a new one....tell them you want a Metra brand antenna adapter. Or, you can do as I did...just cut the original end of the coax cable off and install a "normal" motorola style antenna end.

 

Just repeating what I was told. I was told there was a harness that would work right and it sounds like you got a lead on it.

Any part number for that? I'd like to pick one up too.