I have already pulled the radio fuse and on star fuse. On bcm and under his fuse box #11 is labeled empty. The ignition recall has been done. Fuse 28 on bcm is NOT pulled it is a 2 amp labeled SWC BKLT. The fuse is good. The voltage regulator is in place and connected at the battery. I was at a pull your part place yesterday and noticed a 07 HHR (mine is 09) it had a 10amp fuse in a tiny little box connected to the 50amp maxi fuse at the battery. Mine does not have this 10 amp fuse? Do you know what that’s about? There’s nothing in the power outlets or obd connector and yes there is only 1 wire at the rear of the under hood fuse box. It reads whatever the battery voltage is at any given time. The “ jump post” at front of fuse box also reads battery whatever the battery voltage is. I did not loosen the 4 fuse box bolts before I tightened them but I did tighten one so tight that it just spins now yay. I have had the car 3 months and it’s been a problem since day one. I had to have a locksmith do all keys lost to get it back bc my daughters mother would not give the car back and she ain’t doing right, and it’s my car. My daughter lives with me anyway so I wasn’t going to have her out in a car in my name with my insurance up to no good but she wouldn’t give me the keys. The voltage drops to 12-12.2 about 10 minutes after turning the car off. I figured out about the “ trick “ bc I was fooling with it all afternoon into the night one night and just left the switch on with a charger on it and came out the next morning and the security light was off and the car cranked up. I strongly believe it is a voltage issue but I’ve yet to do a parasitic drain test this weekend as I’m physically limited and it’s been a rough weekend. I know how to do the test. Again, I’m not mechanically challenged but this HHR is whipping me.

 

Sorry, I tried to answer all these questions days ago but it said my post had to be approved first and never was. It’s ok though I just noticed that so there’s all the answers firemangeorge and donbrew yall was asking about

 

Charge battery disconnected so it will charge fully

 

The 10A fuse on the 2007 was for after market something, not standard.
The "jump" post is attached directly to the battery and the starter/alternator.
Seems like, something that is supposed to turn off with the key out is turning on instead, like a relay wired to Normally On.
Does the fob work for doors and remote start (if equipped)? If there is a remote start option in the DIC it is equipped.
Try pulling fuse #17 on the BCM. That is the fuse that keeps the window switches active between key off and driver door open/close.
Try pulling fuse #26 on the BCM. That controls the door lock/unlock relays, actually transistors on the back of the BCM.
Is anything using any of the "unused" fuse positions on the BCM? Any fuses in those positions?
Was there ever an after market radio?
I have heard that the alternator can turn into a motor if a diode is bad.
That is about everything I can spitball.

 

donbrew I agree, something seems to be not shutting down when I turn the key off. I will try pulling those windows and door lock fuses and see if that makes any difference, which also a parasitic draw test would tell me but pulling the fuses you said is quicker and easier and I’m not moving too good these days so I’ll let ya know if that worked if not I will do the testing. From what I can tell the radio has never been removed. It’s stock and I see no evidence of ever being removed, also I’ve already pulled that fuse. I didn’t get any key fobs when I bought the car but it does have remote start option bc there are wires at the hood latch. There are no fuses in any of the “ empty “ spots in either fuse box.

 

I just went out and pulled those fuses, while I was out there I checked under hood fuse box and relay for run/crank is warm. # 51 under the hood

 

That is the problem. Try replacing the the run/crank relay, it is not supposed to be activated when the key is off. Hopefully, it is just welded closed.

 

But they said they have been leaving the key “ON” and hooked to a trickle charger.

 

Correct firemangeorge, it’s warm with the key on and on trickle charge.

 

I will be performing parasitic drain test TODAY. I will update with my results when I get them. I’m truly hoping it’s not the whole BCM.