Hi, I'm new to the platform and to HHR's in general. I recently bought an 08 from a previous owner so I dont have a users manual. I accidentally let the battery die and it sat dead for about 3 weeks before I was able to jump and then also replace the battery, and since then my power locks and radio wont work. The radio has no lights on what so ever and is completely unresponsive. I thought I read somewhere these 2 things could be related in some way. Any advice other than "take it to the dealership" would really help, thanks!

 

There is a link in my sig for Owner Manual.

My first guess without knowing the year of the car is the RDO fuse. #23 on the BCM (the fuse box on the passenger side of the waterfall).

If it is a 2008 there could be other problems. Was the car jump started? If so where were the cables connected?

 

Its definitely a 2008, and yes it was jump started. The cables were attached directly to the battery itself in the back by the spare.

 

Probably the fuse the RCDLR and the radio are on the same fuse.. After a no voltage condition 2008 models RCDLR forgets it's programming. The fob may not work and the tire pressure monitor system may not work; if you have that then you need to get a dealer to update the RCDLR software.

 

As for the radio, if the face plate is blank, then it’s toast!
Mine and some others succumbed to a direct short if the positive cable end touch ground, even after the negative cable was disconnected.
The power retention always current to cause this inside the radio .
There is a shop in Florida that can repair it , or purchase a replacement radio .