If anyone has suggestions...

Here's the history:
1. Had the car for around 6 months - never a problem.
2. Hooked it to my Deltran charger (which I usually do if it might sit a while) until it showed full charge.
3. Unhooked the charger & let it set for 2 weeks (trying to see if I had any excessive battery drain after reading posts regarding such).
4, Hooked the Deltran back up after 2 weeks, & it didn't take long to show full charge, so I assume I have no excessive battery drain problem.
5. Took the charger off & the car sat for about 3 days before I tried to crank it and nothing.

When I get in the car, everything seems normal - dash lights come on, hit the button for driver memory (seat moves in position) - when I hit the starter not a peep outta the starter AND the dash lights go out - or at least the speedo & tach lights along with the info center showing a straight line.

When I let off the starter button, the dash lights come back on and the info center comes back up as it does originally.

If I don't have much luck tomorrow, guess I'll take the battery out and haul it to be tested as I know batteries can be tricky when they go south.

I've got it back on the Deltran charger - going to do some troubleshooting tomorrow - will see what the battery reads with a voltmeter, but that's a hit / miss (need to load test the battery).
I was hoping it would fire up so I could drive to O'Reilly's and have them check the battery (they say they have a load tester) - they're the only parts store that shows the same battery as I have in the car (AC Delco 90PS) available.

I did notice when I put a regular charger on the battery, it seemed to be pulling more amps (on low) than I would have thought it would if the Deltran showed the battery fully charged - will try that again tomorrow to see what it looks like.

EDIT: Forgot to add - I have no idea how old the battery is - can't see anything that would indicate mfg. date as it sits in the car - could possible be the original battery, which would make it 8 or 9 years old.

 

Try to jump start it from another car. That would tell you if your battery is at fault, or if you have another problem. Good Luck!

 

I'm finding a LOT of threads in here with similar problems as myself, BUT it seems NOBODY that starts such a thread tells what they eventually found the problem to be!
I ordered a Schumacher Batter Load Tester from Amazon - should be in Wednesday. Didn't realize they were so inexpensive, and I've got enough darn vehicles now that it will be a handy tool to have.

From a previous post, I held the bottom of the ignition switch long enough to go into accessory mode & checked my battery voltage - shows 9.5 volts, and that's after my Battery Tender showing battery was fully charged!
I put my multi-meter on it and it reads 12.9 volts, so now I'm confused (which reading is correct)?
From other posts, you need at LEAST 11.8 volts to start the car, and that is minimal.

Searching indicates the code on top of my battery shows the battery was made December 2017.
It's an AC Delco P90S with code P127R - 12 should be December, 7 should be 2017 (R is where made)

Was ready to order a replacement battery until I checked voltage with the multi-meter.
Now I'm thinking I'll wait until Wednesday when my load tester arrives.

Unlike most, I WILL post a followup whenever I solve the problem.

 

I think you are on the right track by checking out your battery. I only want to add that once you get things back to normal, it would be a good idea to take a key-off battery drain amperage reading. A rule of thumb for most cars is around 25milliAmps, but your car may be a bit different. Once you know that value, it will serve as a benchmark for you in the future if you suspect your battery is being drained excessively while parked.

 

I'm guessing the 12.6v reading with my Fluke meter is not the most accurate as meters "may" tell you if a battery is dead, but will NOT (definitively) tell you if a battery is good. I tried to explain this to some motorcyclists back when I was riding, but some swore by a meter being better than it really is AFA checking batteries.
(I'm a retired industrial electrician)

I'll probably bite the bullet & go ahead & pick up a Duralast from AutoZone this evening.
Going to yank the old battery & have them load test it, but I'm guessing the 9.6v in the dash readout is more accurate than the Fluke as it's probably battery voltage with a load - when I went into accessory? mode, the fan was blowing on a lower speed, the dash lights were on, & I assume the DRL's were on (Morimoto headlights).
With that load, I'm guessing true battery voltage dropped to 9.6v as indicated, and that ain't gonna start it based on what I'm reading.

Was going to get a direct replacement from O'Reilly (only place locally I could find, & they have to order) but I started thinking about warranty & availability should I be on the road & have battery problems.
Checked Walmart online & called, but nobody working in the auto section since the pandemic - their battery is lead acid - wanted to ask them if you have to add water as there are so many variants these days you can read 'til your eyes bleed & still not have a definitive answer.

My other 3 vehicles all have Duralast from Autozone, and they've held up well (9-24-13, 11-19-12, & 8-20-12).
They've got it on the shelf, so if mine load tests bad, guess I'll bring one home & install.
I'd be a little upset if I didn't get more battery life than "conventional wisdom" seems to indicate these days.

I have no idea on the car's maintenance history - I'd be willing to bet the battery has been thru a number of deep discharge cycles which ain't gonna help battery life.

Guess I'll have to make sure I leave the Battery Tender on it any time I'm going to let it sit for a week?

I am going to eventually get an amp reading to see what kind of parasitic current I have.

I'LL BE BACK!

Folks with all these similar posts that don't come back with their solution just leave us with a bunch of questions.
Doesn't do much for troubleshooting edumucation....

 

Clean your battery cables and make sure that they are tight. Check the starter connection also.

 

Never got that far since I thought I'd tackle the battery first since I was getting such conflicting readings (Fluke vs. DIC).
'Course normal eyeballing showed clean terminals and I did check battery connections for tightness - sounds like you might have to get the car in the air in order to check the starter. Since folks say that's a weak point on the Corvette, next time I have it on the lift I'll eyeball it.

I let the Battery Tender show full charge, took battery out of car, took to AutoZone, and their load tester showed 10.9v.
Assuming he knows his stuff, AutoZone guy said borderline BUT if I had it fully charged on the Battery Tender, he's guessing bad.
Then there's the fact that folks in here say you need 11.8v minimum in order for starter to engage.
I meant to ask him what brand of tester he was using, but it looked a lot like the Schumacher BT-100 I've got on the way.

Anywho...
Bought a Duralast T5-DLG, brought it home, installed, and EUREKA...IT'S ALIVE!

Now for the technical info regarding my attempt at troubleshooting:
1. Old battery read 12.9 v with Fluke meter BUT only 9.6 v in DIC with normal load when you get in the car (dash lights, radio, interior fan on lowest setting).
2. New battery reads 12.2 v in DIC (up from 9.6 v with old battery).
3. I stuck the Fluke inline with the positive terminal before I hooked up the battery - shows .01 to 0 draw on the system (meter fluctuated), but I'm wondering if I may need to try that again after the car's been up and running for a while? Someone in here said if you read anything above .02 amps you have a problem ( I think I had it on milliamps scale in order to get a reading).

I have the new battery in the car with the Battery Tender on it - after it shows fully charged, guess I'll venture out and make sure everything works.
I did re-index the windows - all other settings seem to have been saved BUT I show 0 on all tire pressure readouts.
I tried using my $10 TPMS reset tool (worked before) but no luck - put the car in TPMS learning mode, but never got a horn beep when I tried to reset the first / front left TPMS sensor. I'm going to drive it around a bit and try again, assuming the TPMS readout doesn't come back on its own.

I do have one more problem I either caused or uncovered although I tried to be easy moving wires - I have a broken ground wire leading who knows where?
It's a very small wire (18 gauge or smaller), and is with a bundle of small wires on a ground clamp located almost under the battery tray (there's another identical bundle / setup near it but not hidden by the battery tray). It's attached to the ground but no longer goes wherever it did - the wire is about a foot long and I haven't found the other end.
I've got a feeling it's been like that - guess I'll have to eventually track it down.

 

Based on my attempt at troubleshooting I went with the battery first AND I had a screwy battery problem in the past on my Kawasaki Concours.

Was riding down the highway @ 60mph and the bike died - pulled to the side of the road, wiggled a few wire looms, and the darn thing fired back up.
The shop couldn't find anything, so they replaced the battery and problem never came back.

Found out later the battery company had a batch of batteries go out the door with bad welds - over time, the vibration apparently broke the weld and allowed the battery to short circuit internally. On some batteries you could stop and the shorted metal piece would break contact, and away you go until vibration repeats the problem.

I think the guys on the Gold Wing forum uncovered this one - my Concours used the same battery as the Gold Wing.

 

Took the car out for a spin last night (will hit it again tonight) to check everything out - everything seems OK.

For future reference when troubleshooting (batteries), I'm keeping these notes in my records.

With a new, fully charged battery I read 14.2 / 14.3 v when driving - when motor is off & I go past Accessory to "full on" mode, the DIC reads 12.2 v with normal items on as when I get in the car (radio, dash lights, had blower on low setting). Guess you can use this process as a poor man's battery load test.

The Schumacher Load Tester I ordered should arrive today - going to use it on the battery to see what kind of readings I get.

Curious to see how it reads on my other vehicles - got too darn many and have to stay on top of the battery state on some of them that don't get driven much.

 

Yeah, my battery looked new. Had no idea how old it was since I bought the car used.
I had slow starts and sometimes none at all.
Fluke and DIC both showed 12.4v.
I finally got the meter in a place where I could watch it and tried to crank the car only getting a click.
Both Fluke and DIC showed 8.2 volts. As I let it sit - without being on any charger or tender, I watched the voltage come back up to 12 volts.

BTW, I was sure it was the battery. Took it to one of those places where they test for free. Guy said battery was fine. Then when I started the car he said my alternator was bad because it was only putting out 9 volts.
WTH? I went home and tested at the alternator and I was getting 14.2 volts.

There's a post here somewhere that talks about the sequence and places to test voltage. That's what I used to finally determine (again) that I had a bad battery.
Look at post #53 here.
https://www.corvetteforum.com/forums...running-3.html

Replaced it with an Optima and has been perfect ever since.