UPDATE: Well, sometimes, things just don't make sense, especially with the erradic readings I was getting, and that the vette did kick over a couple times during the course of trying to figure out what was happening.

This is what happened: The Optima battery has a top post, which was too close to my cruise control bracket, the bracket ended up cutting a wedge into the top post, which in turn damaged the battery, and just made it wacky! Took the battery to Murrays, within less than 30 seconds, the guy told me it was junk. Put a new battery in, and started right up. BUT, now I either have a bad thread on the negative cable or post! Won't tork down tight enough . . . always something! Back to Murrays I shall go! Thanks for all the ideas and suggestions.

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ORIGINAL POST: Okay guys, gotta pick your brains here, I really need guidance. My vette is a 96.
Put a new battery in about a month ago, all was going well.

Went to start it one morning, totally dead! I'm almost positive, that I left the dome light on. Okay, not a biggie. So, I charge the battery, the charger shows its charging and at one point fully charged, but the car is still dead. I would have hood/interior lamps lit for a second, until when I go to start the car, nothing - dead, and off go the hood lamps and interior lamps. Readings on my battery tester were going crazy, jumping all over the place, from 5 to 12.3 down to 1, back up to 12, made no sense.

Today I was at the point where I thought the new battery was defective. So, I start unhooking everything. I Realized that the positive top post of the Optima battery was touching the cruise control bracket, and the bracket actually cut into the top post. Okay, thinking this was part (if not all) of my problem. Next, I really cleaned up the battery cable with a wire brush, so now I have got nice clean connections. Temporarily set the battery back in the tray, (keeping the top positive post away from the metal bracket) temporarily hook up the cables, I SEE LIGHTS! Go to start, starts right up! I'm thinking . . . COOL, I'm good to go! Right?

Take battery out, cut off the top positive post, so now I have lots of clearance. Everything is looking good. Connect the cables temporarily, once again, see lamps lit, go to start starts right up! Thinking alls good again.

Next, I put some dielectric guck on the cables, set the battery in the tray right, and start cranking and connecting everything. See hood lamps, go to start the car, completely DEAD!

Okay, thinking the gunk did this, so I cleaned that off, wire brushed the connections again. Reconnect everything. . .Go to start, NOTHING, totally dead.

This is the wierd part. (read carefully)

When I test the battery with both cables OFF, and I test against the battery posts, I'm getting 12.3

When I connect the cables, and tested the battery connection against the cables, I'm getting NOTHING

When I have the positive connected and disconnect the black cable (negative) and put my tester on the positive cable and against the negative battery POST, I'm getting full 12.3 reading.

What on earth is going on? and why did it start 2 times NO problem? My mechanic hasn't a clue . . . my friend who was helping me is stumped . . . I need your help.

TIA and help me get this thing on the road, so I can make this Saturdays Dyno.

[Modified by 96KICKS, 8:34 AM 4/22/2004]


[Modified by 96KICKS, 9:42 AM 4/22/2004]

 

Were you able to do a load test on the battery? A battery can give a good voltage reading but still not have enough amps to start the car.

 

That's what we were thinking too, but during working on it, (connecting/cleaning etc.) it started strong two times.

 

there is a chance that dead shorting it harmed the battery in some way.

additionally, just starting it does not kick off the charging process...

 

I suspect the battery has internally shorted and is now junk.

Easiest thing to do is to swap in another battery and see if the car starts; if it does, you'll know it's the battery.

Jake

 

It sounds like you lost a cell in the battery...go get a new one and you should be OK :thumbs:

 

You may put some stress on the battery when it made contact with the frame - maybe then killed a cell when you started it the time before it when kaput.

Swapp it out with another and you will know if it's and electrical prob or just the batter

 

:iagree: with Ruby and Mako

Replace the cables as well. I've seen cables that corrode after the terminal connector, and under the insulation. You would never know they were bad from the outside but were corroded enough to cause high resistance and a no crank situation.


[Modified by Chevy Guy, 9:25 PM 4/21/2004]

 

Sounds like your ground cable is not making good connection at the post. Especially since you say that the light under the hood will sometimes be on and than an instant later it turns off.

With both cables connected trying measuring at the posts (probe at the same locations that you did with the cables disconnected). If you have 12V with at the posts with the cables connected, but 0V when measuring on the cable, than this pinpoints that there is a connection problem. If it measures 0 at the posts with the cables connected then the battery is most likely dead.

 

I had a similar problem, my starter took a dump, I replaced it and all is well.

 

I would take it to a auto parts store to have a load test done on it. They normally do it for free. I also had a friend with a ZR1 that was giving him fits would not start and drained the battery. Come to find out it was the starter. Replaced it and now all is good. So you may check that if its not the battery. I have also had bad grounds give me problem.

 

Replace the ground cable. Test by removing ground cable and connecting jumper cable from battery to engine ground, if it starts replace ground cable. May have burnt it up when battery shorted out to cruise bracket. All those amps went through the ground too.

 

:iagree: :yesnod:

 

:iagree: with everyone-my bet-it's the starter :thumbs:

 

It was the battery, read my updated post, and it explains what happened.