2006 2.4 LT automatice
No problems, no weird noises, no issues at all until this morning, halfway to a job site. Smelled something a little hot while I was on the freeway, but couldn't determine (at the time) if it was something else outside or mine. (20/20 hindsight, definitely mine!)
Still no warning lights or issues at that point...a few more miles down the road, AC stopped blowing cold air. As I slowed to a stop to turn into my destination, I noticed smoke coming from under the hood. Turned the fan off, and pulled into my jobsite, parked...didn't see anymore smoke or smell anything electrical burning. (By the time I parked, there could have been a warning light on, but I didn't notice any)
Came out on break to see what I could see and try to diagnose the problem, tried to start her, no luck. On the initial attempt, started to turn over but didn't start. End of day, had a friend try to jump me--went directly to the battery terminals, NOT the remote terminals under the hood. No dice. Metered the battery, appears to be fully charged. Consensus from the friends helping me was 'dead alternator'. (Belt appears to still be intact and healthy.)
Home now, car still at jobsite until I can either get it started or towed somewhere tomorrow.
Suggestions and advice welcome! Info provided in this post is as complete as I can make it as this time. Auto repairs really aren't my thing, but I have been known to successfully undertake them! (More so with my diesel truck than with the HHR)

 

Could be either the A/C, alternator or belt tensioners bearing froze up. Could be a wire fried.

 

Welcome to the site, I'm thinking time for an alternator, might as well change the tensioner and belt while your hands are dirty!

 

Is there any way to determine if the alternator is fried without pulling it first?

 

My suspicion is the bearing locked up, so yes. Take the belt off and try to turn the various pulleys.

 

Yes, any auto parts store can diagnose it for free (most likely) - but it has to be running for that. Also if it is running, a simple volt meter can often indicate if it is charging (it should give a reading of ~14 volts rather than the ~12 volts that the battery alone delivers).

When my alternator went - there was definitely a burnt electrical smell, and a hint of smoke coming from the alternator.

 

Not running, which leaves out my friendly local auto parts store! At this point, mostly trying to determine if this is one I can handle on my own and can just have her towed home or of not....
(assuming that access to this area includes pulling the wheel and all the obnoxious plastic parts, which I can do.)

 

Getting the belt off can be a trying experience. The easiest and most expensive way is to buy a serpentine belt tool and cut the handle to about 13 inches. Harbor Freight has them on sale frequently for about $13. The full length will not work because of things under the hood. If you can find/fabricate one that has the 3/8 square mounted at 45 degrees instead of 90, that will work.

The Service Manuals are all just wrong for HHR.

 

A little short on fabrication space and tools where I am now. (Basic hand tools with me, everything else still in storage a couple thousand miles away)

 

This one has me stumped too. A/C quit working, smelled something burning ... if the A/C compressor locked up I think you would have heard the scretching, maybe not, but that could explain the burn smell, the belt trying to spin a locked up compressor. If the electric radiator fan died, your A/c would not blow cold, but that does not apply to your other symptoms. I may be mistaken but I think it should take a jump with a dead alternator. When you try to start it, do you hear the starter engage? Do you hear the fuel pump run for 3 seconds when you turn the key on? I am leaning toward something electrical or a bearing locked up on the A/C. Keeps us posted on your findings.