Daddio1

Ok, Here's my DBS story. I have a 2005 manual shift C6. I have been dealing with the dead battery thing for 8 years. I used a battery tender for a few years but got tired of always having to connect it. I have been through the original battery, two Optima red top's, and am on the second Auto zone battery. I always park it in reverse and lock the wheel. I read on the forum that someone had success with refreshing the BCM so I had that done last July. No problems until last January when it died 100 miles away on an overnighter. Then I read that maybe the Lojack GPS module was the culprit. I had it removed and replaced the battery. Two weeks later no problems. When driven on the next wed. all was good. On Fri. dead. So being completely frustrated I turned to the Dealer where I bought the car to diagnose the issue. After two weeks my service rep tells me that after starting it each day that it had finally failed the day before. The battery was dead. He said that they did not have their diagnosis equipment connected at the time and we would have to wait for it to fail again. After another three weeks with no failure they told me to pick up the car. So after $135.00 diagnosis fee. I still do not know what is wrong with my car. After calling GM, all they could do is set up another diagnosis appointment at another dealer for another $135.00. I do not know what else to do.

mikeCsix

I would keep searching the forum, I believe it was the OnStar module that was the culprit for battery drainage. The OnStar system was not being used. I would have it electrically disconnected from the system if you are not using it.

Intermittent electrical problems are really tough to troubleshoot and takes lots of patience.

4SUMERZ

I'm not sure what you have attempted yourself, but if you can hook up a volt/amp multi meter to the battery connections, then you may have a chance of finding what is killing the battery from time to time.
What I have attached are a few items that have been culprits in parasitic drin on the C6 system that drains the battery.
This is some of the same tests that GM techs are "supposed" to do when troubleshooting.

Good Luck

4SUMERZ

Here is a GM checklist (2007) that was used to try to find electrical parasitic drain.

Daddio1

Thanks for the reply.
I would disconnect it but my car did not come with Onstar.

Daddio1

I just ordered a PriorityStart Automatic Battery Protector. We'll see how this works.

undertheradar

I've had similar issues with my '05 and it ended up being the vanity lights in the sunvisors, the little plastic pin that is supposed to turn off the lights when you close the lid on the mirror, wasn't pushing the contact down hard enough (so I disabled said pin by pushing it all the way in behind the bezel to keep it off, yes no light on the vanity mirror but, I don't care) this saved me from 4 batteries in 3 years that kept going dead. I have had the same battery in the car now for over a year and haven't killed it yet.

Homer3D

I am going through a dead battery issue myself on my 2013 but I think it is a result of the battery going bad. I had a 2005 C6 as well and it too would not survive a week without being plugged into a battery tender. Do you have a multimeter to see what the amp draw is when the car is off? You can then start pulling fuses out to see if the amp draw drops. Without a multimeter you are basically shooting in the dark.

Here is my post investigating my issue.
https://www.corvetteforum.com/forums...ar-is-off.html

Daddio1

Thanks for the reply. I'll look into that.

Daddio1

Thanks for the reply. They did a draw test at the dealer the other day. It always comes out normal. They were waiting for it to fail a second time while they were watching it. Very slight chance of that happening. After three weeks they gave up.

Homer3D

Yeah, I took my 2005 to the dealership 3 times and to an independent shop. No one could figure out why the battery was draining to much. I had no choice but to just leave it on the tender when I wasn't driving.