C7 – Dead As A Doornail! (2018 Stingray Base)

1. Running perfectly fine 4 days ago. Starting, charging, all systems functioning, all gauges operational, lock, unlock, lights, horn, etc, perfect.

2. Decided to make some changes to the infotainment system. Pressed start button for 10sec, and made the changes. Shut down, all well.

3. Wanted to make further changes. Held start button for a few seconds, but inadvertently pressed brake pedal. Engine started. Pressed start button again to shut engine down.

4. Exited car, and left garage with C7 in the ‘shutdown’ mode, lights on, expecting it to shut down in a few minutes as it always did.

5. Following day attempted to start car. No start. No dash lights, and door locks not operational.

6. Unlocked rear hatch with key, and opened driver’s door with pull wire.

7. Attempted to start, but no success. Tried everything, no luck.

8. Decided to replace battery, as the ‘non-shutdown’ a couple of days ago may have drained the battery. Removed battery, put on overnight charger.

9. Morning showed 12.4v. Reinstalled battery, but still no system function. Green light came on starter button, but no start. No screen images. Decided to purchase new battery.

10. Purchased AGM Delco, and replaced. Attempted to enter doors – lock system ‘activated’, but only a ‘clicking’ sound, did not open latch on door. Headlights, parking lights, brake lights all activated. Both windows go up and down.

11. Double-checked all battery attachments to verify proper installation. All in order.

12. A previous on-line post indicated 350amp fuse may have blown. Image online showed the battery fuse setup with a 60amp and 350amp fuse. The fuses appeared to be ‘detachable’. However, on this vehicle, the fuses are integrated into the metal plate that attaches the hot cable to the system. Tested with ohm meter, no resistance.

13. Triple-checked all connections, and all positive-negative terminals are tight.

WHAT TO DO??? Need your expertise…all very peculiar, as no ‘warning signs’, and some of the electrical system is operational. Open to ALL recommendations….!!!

 

There's a small black wire near the negative battery cable that people often break or forget to attach. Make sure that's in place.

Based on item 10, verify the new battery is good. The symptoms it's exhibiting are those of a nearly dead battery.

Assuming the above is ok, disconnect the battery overnight and then reconnect for another try.

After all that.....check all the other fuses

 

Thx - really appreciate the reply. The new battery was checked at the shop (Batteries +), and it's 100% You're right, the previous battery was junk, and they checked it when I purchased the new one. Don't know how to check the 350 and 60amp fuses at the battery, as they are integrated into the 12v plate that makes the connection. I'll check again in the morning as you suggest, but if that fails, what to do next? Really hope it doesn't have to go to to Chev dealer...

 

BTW, yes, I ensured the small black negative wire is attached...

 

Can you post a picture of the battery all hooked up? Maybe there's something there that someone will pick up on. Stranger things have happened.

After that, do the hard reset......Disconnect the battery, wait overnight, and then hook it all up in the morning. Don't forget the windows will need to be indexed as well.

 

The main thing is a C7 battery change out is to make sure all the connections are tight. Depending how you took wiring apart for the battery install, there several connections that need to be real tight. I suggest tightening all connections again & that may cure your problem. The issues you are having are common on the C7 battery change out.

 

You need to use a DVM and measure the voltage after the 350 amp fuse and all the other fuses on that buss bar.

All fuses will have some resistance even if it is only in tenths of an ohm.

 

Hi - Want to thank all who have responded with very specific and focused recommendations. I took all of your advice, and last evening double-checked every connection on the new AGM battery. Then I replaced the fob battery and...voila! Everything perfectly operational!! To celebrate, I took a ride in the snow (NH), and all is now 100%! Again, thanks for your concern, advice and very much appreciated assistance!! (...pre-sno pic)