Just a FYI. That is called a BCM on the HHR’s. Body Control Module

 

Your problem is that bundle of added on crap. done very poorly.
I don't think we ever heard when this started or if it has been from the start. All of that stuff the previous owner installed and then got ripped out is the MOST likely cause of your troubles.
That big red wire on the BCM with all the splices is the main power. Only the installer knows where they might go.

 

Excellent news the Chevy HHR 2006 came back to life today went out recheck the starter connections negative bolt was tight but would not tighten so I tightened it put a second nut behind it to make sure it tight when do the BCM Disconnected all the wires that did not belong and eliminated them went under the hood, took the spices out the two that I found went back to try again. I felt so good when the HHR started out I have to say thank you all very much this thread. help me out so much. I forgot about YouTube as I was told and listen to the advice of experts tomorrow I’m going to clean up the rest of the connections with the connection, clean and take the whole unit and wash up that engine bay so I can eat off it👋😃

 

Awesome!

 

I have learned so much about HHR electronics,
in the last two weeks!
😁