Is this an install problem or defect

I recently got a new deck installed in my 2003 Sunfire GT.  They relocated the factory deck using a Metra harness (Metra 70-2003t) and a Metra dash kit.  About a week after the install, I got up one morning to leave for work and found my brake lights on.  I started the car no problem, and then turned it off.  Brake lights went out.  Figured there was a glitch.  Checked out hazard, brake and signal lights with engine on and all seems fine.  So I don't worry about it.  I went away for the weekend a few days later and when I returned, I tried the unlock the doors and found the battery right dead.  I'm assuming the brake lights came on mysteriously again.

So my question is, is this a problem caused by my install, or by a faulty GM part that happened to occur near the same time?  I'm not sure if I should be taking the car back to the install shop or GM.  Any comments or assistance would be appreciated.

J

Sounds like it could be an install problem but it could go either way. when they hookup the radio relocation harness they have to find a switched 12 volt  I don’t know were they got it from , but I normally tap the pink wire in the ignition harness. That is the only splice you have to make on the factory wires on an aftermarket install using the relocation harness, everything else is built into the harness.  I have seen some bad installs that cause all kinds of abnormal problems (not jumping to any conclusions) but I would start by taking it back to the shop and inform them of the problems that arose after the install, and see what they have to say. If they can’t fix the problem put it back to stock and bring it into the dealer. However I would not mention to the dealer the radio install (some times they throw a fit) and see what they have to say.