We have a 2006 HHR and for the last couple of years it has been one electrical problem after the next. It had set for about three weeks and today I went out to start the thing and the battery was dead. I jumped it, let it run for awhile, and drove it about one mile. It's cold so I turned on the heat and the knob to adjust the heat did nothing - I could turn the fan off so as to not bake, but, the heat remained on the highest temp possible and the little aduster knob did nothing. Just checking out that panel I depresesed the button that normally switches it over to AC and that was dead - normally lights up, did nothing. The other buttons - can't even remember what they do - are dead, as well. I think we may junk this thing for all the electrical problems. I was driving it three weeks ago and these things worked (ran the AC). What would cause everything on this panel to act up in this way? I'd love to keep this thing if I could get it running right (we spend $1200.00 on a new exhaust system 2 years ago) but we have had the intermittent, "flashing guages thing", for the past two years and I am about done messing with this car. Anyway, suddenly nothing on that panel which control the heat and AC - with the execption of the fan speed dial - work. Thanks for any ideas.

 

Pull the hvac panel and check the wiring harness connection for melted plastic.

 

Tighten the 4 bolts in the fuse box really tight. They hold the 2 halves of the box together, there are a hundred or so connections under there that work loose.

 

Thanks. I'll pull it apart.

 

And tighten those bolts!

 

Yeah - those bolts are tighter than hell - about as tight as they could be.

 

The bolts are as tight as can be. I disassmbled the thing and took out those controls, disconnected everything - plus I tested fuse number 10 with another fuse. First, just looking at the fuse it looked perfect and swapping another one into that place did nothing - so it isn't the fuse. Nothing looks burned or melted at all. But, now, the fan know doesn't work either. Can that part be burned or fried electronically but not have any outward appearance of a problem? Everything else on the car works - lights, radio, everything. But to look at that part and the connectors nothing looks bad.

 

I assume that is fuse #10 on the BCM?
Does the AC compressor turn on when requested?
The blower motor get power from fuse #4 on the underhood and relay #30 on the BCM. then it goes to ground through the switch to the resistor pack. If the blower only works on high it is the resistors or the switch if it does not work at all look at the fuse, relay or motor. (high goes directly to ground when the relay energizes)
Do the stop lamps work? Not the CHMSL.
Do the mode switch and recirc switch work?
When you reassembled the fuse box did you hear clicks?

 

In desperation - having determined it was not a fuse - I went to (of all things) an AI thing called ChatGPT. I mentioned that I had jumped car from the front (which I now understand is not recommended) and that damned AI thing said something like, "Ah, yes, people have frequently reported that after jumping their HHR from the front terminals the temperature controls no longer work, at all - except for the fan switch which often works for a short period of time. I can almost guarantee you have fried the control board in your HVAC controls" etc - which was exactly what had happened. I was flabergasted at how much this AI thing knew about a 2006 HHR. The fan had worked, just as it described, for one day. I ordered a replacement on Ebay - which turned out to be black and not gray like the old one (black, gray - I don't care) - but that was the problem. I just connected the thing, haven't even replaced the trim, but wanted to come inside and warm up, and, give an update. Thanks for all the suggestions - much appreciated. But that entire control unit was just bad.

 

If you're going to Jumpstart it from the front, you have to connect to the proper points, it's in the owner manual. On the side of the underhood fuse block, connect the red(positive) to large lug under the red cover. Black(negative) to the stud on the strut tower. Do not attach to the small red lug near the firewall, this is the power steering positive.