Getting a tech at Crutchfield that nows what's up with the HHR is like going to the casino, sometimes ya win, sometimes you wonder what the hell you went there to begin with! LOL

BTW, no onstar in my car either.

 

Not to mention their prices are out of sight. I could understand paying a little more if I was getting a free harness like they used to do, but paying $65 for the harness adaptor is a little steep when you're paying $50-$100 more for a HU you can buy elsewhere a lot cheaper now.

And if the stereo doesn't fit the adapters they offer, it "doesn't fit". Like any double-DIN stereo won't fit our car because they don't carry the Metra or Scosche double-DIN trim adapter.

 

I was going to ask you how you did it, but someone beat me to it first! I find it funny (or maybe sad) that the Crutchfield site says you'll loose your chimes & Onstar on the HHR and then also sells the GMOSLAN03.

I have also seen mentioned somewhere that you can wire a relay into the GMOSLNA03 to get the tic-tic for the turn signal - the relay controls nothing, it is just used as a mechanical noise maker.

I've ordered a GMOSLAN04 for my system (not from Crutchfield) . I hope I didn't make a mistake, 'cause I'm still confused about the amplifier situation and the 04 is for amplified and the 03 is for non-amplified.

I would also like to do the steering wheel controls, but I don't have the remote for my HU and I'm not sure I can program the adapter without it.

 

Some progress?

I have removed the wired in harness for the aftermarket head unit and wired up the HU to the GMOS-LAN-04 harness/adapter. It's all very clean with the two factory radio plugs connecting into the GMOS-LAN-04 harness with no extra wires. A quick test has the chimes and the Onstar working! However the output of the HU is very low, I have to turn it up to full volume just to get something loud enough to listen to. I have a few more things to test and questions for Metra tech support. One thing I'll say for Metra support is that they are very quick to respond. I'm still waiting to hear back from Pyleaudio support.

I did find an error in the previous installation. The front left positive lead was crossed with the front right positive lead.

 

Sounds like you're getting it worked out.