Frankie15

Hey guys,

I did do numerous searching on this topic, but I have slightly different symptoms and I wanted to get some of your input.

Here is what has happened so far:

• The battery voltage on the DIC reads between 11.9-12.4 V usually when the car is turned off.
• Sometimes it will take three times or so to start the car. Sometimes it will start up on the first attempt. I usually will just hear a single click and then it will fire right up after two more attempts.

I have read numerous other posts regarding the alternator/horn relay. My horn works just fine and the fuse looks okay. The battery is only 7 months old, BUT it has completely drained before by accident (happened 2-3 months ago) which required a jump start. The battery will instantly show below 12.6V when the car is turned off.

Could the alternator be the problem if the battery instantly jumps to 14v (or eventually to 14v) after the car is started? I am assuming my car is having intermittent starting issues due to the low voltage. What should the voltage be on the DIC before starting the car?

It seems like the battery is unable to hold a charge, but it seems unlikely that a new battery is necessary after only 7 months.

Would greatly appreciate any input. Thanks guys!

4SUMERZ

You say that the battery went completely dead 2-3 months ago? That my friend is not a good situation for a battery, let alone one for a C6.
You most likely now have a shorted cell, thus why the voltage is down a bit, charges back up, but doesn't last long.
I had the symptoms of a battery that I had that went dead (my fault). Once I charged it up, it would never keep a charge too long, and after a day of sitting, would just barely start the car.
I got all kinds of weird and wonderful alarms, lights, etc. My battery was a 6 month old battery when I killed it.
When you jump started a dead battery, you knocked off a bunch of lead deposits to the bottom of the battery, and that will eventually short out a plate cell, which sounds like it already has.
I had to get a replacement, and no issues since, 4 years now.
I keep it on a tender when it's sitting for more than a few days (seldom happens) and it is on a tender all the time during the hibernation period.

You can check for connections at the battery to make sure they are all tight, at the starter solenoid.

When a battery will no longer hold enough charge to reliably start the engine, it's time to replace the battery. Lead-acid batteries deteriorate much faster when discharged due to a chemical process called sulfation, a non-reversible chemical reaction. Sulfation causes deposits on the battery's lead plates that increase internal resistance and interfere with the ability to take a charge. Sulfation happens much more quickly when the battery is discharged than when it is fully charged. That's why it's important to check your charging system if your battery seems to be pooping out. A weak or marginal charging system leads to battery sulfation and premature failure.

As for the alternator, if it reads 14+ volts when the car is running, it's A-OK.
The alternator is used to keep the battery fully charged, but it s not meant to bring a dead battery back to life.
An alternator is a car trickle charger, so to speak.

1968swbbigblock

I would look at your connections on the starter 1st. Check for looseness and corrosion of the battery lead and hot crossover wire.
2nd check the plug on the back of the alt. Check for tightness and corrosion.
After that look at replacing alt

RICH 28

Just get a new battery since yours is under warranty. If you still have problems, then you will have some trouble shooting to do.

ringo11

a 12v lead acid battery with 100% charge will read at least 12.7v
your reading of 12.6v after charging is a sign of impending doom and despair, as it will surely go out at a most inopportune time.

Frankie15

I figured letting it letting it die to the point where I needed a jump was going to be pretty harmful. I will pick up another battery this weekend and see if that resolves the issue.

I have to jack up the car to gain access to the starter, right? Thanks!

Unfortunately, the previous owner replaced the battery the day I bought the car. Had an issue where the doors wouldn't unlock and the battery tested as being undersized for the C6. No warranty since I didn't buy it. Would've been nice to be able to replace this under warranty.

Yeah, it is limping along right now but I can totally see the battery just crapping out at the worst time. Thanks!

Corvette_Ed

You shouldn't have to be the original buyer of the battery to return it for warranty replacement, but either way, try to return it for a replacement. The worst they can do is say no.

Bigredwing

A free battery test at Autozone or someplace similar should answer your question about the battery. My OEM battery only lasted a couple of years and I use a battery tender regularly.

Frankie15

I thought of that, but I don't have the receipt. I did try to contact the original owner to see if he still has it, but its doubtful.

Corvette_Ed

When I had my C5 the AC Delco battery in it went bad and needed to be replaced. This battery was already in the car when I bought it, and it was about two years later that it went bad. I took it down to a local AC Delco dealer, and the battery was swapped out under warranty, although at a pro-rated cost. I didn't have the receipt either, but they still replaced the battery under warranty.

Frankie15

Thanks. We got the battery at Advance Auto. I called my local one and they informed me I need to contact the original Advance Auto I bought it from to get the transaction code. I bought the car about 4 hours away from my location. There are three Advance Auto stores around where we met. I know we went to one of them. Going to call each one and hope one of them has the transaction code for me. Thanks bud!

unixcorn

I think this is the best advice to start. When I bought my 2008 Vette at a dealer, they had just replaced the battery. When I got in to test drive it, the Service Charging System warning message popped up. The salesman insisted we take it for a cruise to "charge up the battery", assuring me that would take care of it. I had a two hour drive home so I was concerned. The test drive proved disastrous as the car died on the Interstate and had to be flat bedded back to the dealer. I still bought the car but they had to install a new alternator. The car had 12K miles on it. My point to this long story is that I believe your alternator is telling you it's time to replace it and I would be listening.
Please keep us posted and good luck!

Frankie15

Just got back from Advance Auto. The guy tested the cranking amps of the battery and it was between 650 and 700 which he said is totally normal. I asked if he could test the alternator, but he said it shouldn't be the issue since the car will read 14+ volts when the car is started.

Update 2:I decided to bring it to another Advance Auto and he had me attempt a load test while he monitored what was going on with the testing machine. I turned on the high beams, AC, rear defrost, radio, and the heated seats and the voltage barely dropped.

I just can't get over the fact that the DIC panel will say the battery is around 11.8V to 12.2V when the car is off after sitting for a while. Shouldn't it be 12.6 V? I am trying to understand how the alternator could be the culprit if its doing its job of keeping the battery over 14 V. There were two times when this took several minutes, but now its instant after starting the car.

Update 3: I took it to a shop today just to check the battery (one that I trust 100%) and everything checked out fine with the battery and the alternator. He also performed a load test which passed. They were super busy today and I was lucky enough for them to squeeze me in for this. I would've liked to have them check out the starter, but I will try to look into it.

I also performed a load test inside the car using exactly what the guy did in this video:


My voltage did not drop below 13.5 V. It stayed at 13.5 V for a split second and mostly hovered around 13.6V - 13.8V. Definitely didn't drop to 12.7V like in the video. Went up to 14 V or so after driving for a little bit.

I am going to check what the voltage is in the battery after sitting overnight with a multimeter. If it checks out and shows 12.6 V then I am going to start investigating the starter. Thanks for your help guys!

Frankie15

Went outside to check the battery after it sitting for 4 hours. The reading on my multimeter read 12.6-12.7 V and the reading in the car said 11.9 V. I was initially thinking there was something causing a slow drain while the car was sitting, but it seems that the gauge is just not very accurate when the car is off. I will check it again in the morning as I usually have a difficult time starting when it sits overnight.

All signs are pointing to an issue with the connection at the starter. Is it possible to see these wires without getting under the car?

Thanks guys!

ringo11

perhaps there's that much of a voltage drop between measuring voltage directly at the battery vs where ever the car is picking this voltage from.

Frankie15

I checked the battery on the car this morning. I didn't leave the hood open or anything so I did have to unlock the door and release the hood. It measured 12.3 V. It did start right up on the first attempt. I had a quick trip to the grocery store which was about 4 miles. When I left, it did take two attempts to start the car to get going. I hate how intermittent this issue is. I thought it was just on cold starts, but it happened after a short trip from a cold start.

Does this definitely seem starter related? Is there any way to see the starter and the connections without getting under the car? I made a post in tech in the event that it was more suitable in that forum. If I cannot see anything from the engine bay, I will have to take it to my shop next week. Hopefully it will continue starting.

ringo11

Seems a proper pair of drive on ramps would be handy about now. I do recall reading where corvette owners of front mounted batteries had found connector corrosion below the battery tray. You might remove the battery and check for that. Be sure to apply dielectric grease on the connections before plunging them back together.

Frankie15

Thanks to everybody in this thread who offered some assistance. It was in fact the starter solenoid. I know this issue is common with headers, but I have stock manifolds. Everyone should definitely keep an eye on this. Got it replaced and she is as good as new. Here is the pic of the solenoid:

ringo11

Well that's ugly...how many miles on that?
Glad you found it though, simple enough fix

Frankie15

Tell me about it. 2008 with 60k miles.