My 1996 C4 has been off the road for about 16-months. One of the reasons was to rebuild the steering column because of a wobbly tilt mechanism. Because of this, the car was not started for most of this time. The battery in the car was brand new, but because of a mishap with my trickle charger, the battery wasn't being charged and it ran down to zero charge. So, now the column is back in the car (wobble free!) and now I can only get my Corvette to start by jumping it with my Bonneville.

My dead battery was reconditioned, out of the car, with my charger which has a function for this. The battery now holds a charge with normal voltage, and easily passes a 100-amp load test. When I try to start my Vette without jumping, the dash lights up at run, all active accessories light up, but when I turn the key to start, there is one loud click and then whole car goes dead, no dash display, no interior lights, nothing. The car stays dead until I pull the cables off the battery, and wait for the residual voltage in the Vette to bleed off. At this point, I reconnect the battery, and wash, rinse, repeat.

Any thoughts on this? I am utterly puzzled.

 

Classic case of a bad connection somewhere. When the "whole car is dead", what is the vour batt voltage at the batt posts? I'm guessing 12.Xv. Now, what is your voltage at the starter? I'm betting "0v". Work your way back to the battery to find the point of lost continuity.

 

If it starts when jumped but not with the battery alone it has to be the battery since that is the only variable. I am not sure about the conditioner you have in your charger completely “reconditioning “ the battery. From your description of the symptoms it sounds like there is insufficient amperage being delivered by the battery. Can your charger measure both voltage and charging amperage? Do you have a way to measure amperage with a load on the battery?
Charge your battery, try to start the car with only your battery, and then measure battery voltage after trying to start. From the symptoms I would think your voltage may show a drop after the attempt.

 

The car going dead seems more like the PCM getting its brains scrambled by the voltage at crank dropping below some vital threshold. When I worked at a Subaru dealership, if a Subaru battery got all the way run down, the car would be dead untill the battery cables were shorted. This would discharge any remaining charge in the car's electronics and clear the car's electronic control module. After this, and the install of a fresh battery, it would start.

 

My load tester is a standard Schumacher type analog tester that will load testing at start, so I am putting a fresh charge on the battery, and once it is back in the car, I'll test the voltage drop at crank with my tester and see if it is in the normal range (10.2 volts, minimum).

 

I agree with tom, sounds exactly like a bad connection somewhere, clean your battery cable ends well and check that your grounds are tight and clean. Doubt its the battery if its passing a load test. Clean all your connections and make sure they are tight and I would bet money it would fix it

 

I hear you This isn't a Subaru though. TEST. See with your eyes, what is going wrong.

 

Connections might be a culprit but it sounds like if you use your Bonneville to jump the car it starts and stays running. Is this a correct assumption? If this is the case since the additional battery from the Bonneville is connected in series it does not supply a higher voltage than a single battery but does allow the combined batteries to maintain a voltage of 12+ volts throughout the starting cycle. Maintaining that voltage may be what is allowing the connections to be made across a corroded connection since voltage is what supplies the “push”. It also shows that the single battery can not maintain a high enough voltage to get the job done.
I will be interested in the solution once you find it.

 

Thank God it isn't a Subaru! I respect Subaru's engineering, longevity, and their dead-serious all-wheel drive, but the only Subaru that really got me fired up was the BRZ, which is the most un-Subaru Subaru you can imagine!😆

 

Yes, your assumption is correct. The Vette runs like a top after being jumped and disconnected from the Bonneville. It's supposed to rain/thunderstorm off and on until Friday around here, so the only thing I will be able to diagnose until the weather turns around is my passenger footwell leak. So, at least I've got that going for me. 🙄

 

I went through this on my 84 Mustang GT once. While my connections were good, I finally found that one of my battery cables had hidden corrosion. Cable looked fine from the outside. I found this because I had the exact same click/die, then I would wiggle the cables and be back at square one.

Just a thought.

 

And in my message it should have stated in parallel not series. Too late in the evening to think about electrical issues.

 

The rain was delayed so I was able to work on the starting issue and I have an update: It is almost certainly an issue with the starter.

Today, I jacked up the car enough to access the starter solenoid terminals and clipped on a remote start switch to the "S" and "B" terminals. I hooked up my load tester and with the key out of the ignition, hit the remote start switch. The solenoid clicked loudly, and...nothing. The starter did not crank, volts on my tester showed 11+ volts. So, I said eff it, and hit the remote again, and this time the starter cranked with the volts showing 11.4 while cranking, and the starter sounding strong. So far so good.

Next, I put the key in the ignition, i turned it to run, and the hit the starter with the remote start. The engine fired right up, again with the tester showing 11.4 while cranking. Remember, below 10.2 volts was the failure spec, so my battery was showing good volts while cranking.

Lastly, I pulled the remote start switch off the solenoid, got behind the wheel of the Vette, hit the key, and it started right up! I let it run for a while, turned it off and restarted a few times with no issues. The overly optimistic part of me says the starting issue was caused by the car being outside (under a $$$ cover) and not being started for over a year. The more realistic side says I need a new starter. Just FYI the starter terminals were tight and corrosion free, but there was a good amount of oil on the starter (not really sure how relevant the oil is). I still have no clue as to why the car was blanking out earlier when it failed to start as the battery is certainly working properly.

Any thoughts? 🤔

 

I have thoughts. I shared them with you right here:

I still think you have/had a bad connection. It's working now...

 

Here's an update of my starting issue. Since my last post my Corvette has started with no problems over and over again, so my starter seems to be perfectly fine. The only actual problem I found was with the positIve battery terminal bolt, which had been hard to get started when tightening it to the battery. This may have been causing the car to blackout after an unsuccessful start. When I realized the bolts can just be popped out, and when I did this with the positive terminal, you can see what I found below. I got a replacement pair for $2 at my local Auto Zone, so it looks like I am all good now!


Yep, threads are kind of striped. Not my bad, though!
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Yup had the same issue had a striped bolt to my battery too . Better yet i had the car to corvette shop who replaced battery , battery last just 2 years and this issue drove me nuts during the 2 years . I had to replaced battery and battery bolts and put a quick disconnect to turn off battery while in storage glad you found no fun ps will never never go back to corvette shop very expensive and service why to shallow . Why people dont go their anymore .

 

Glad to see you got it figured out before I reminded you there is one other connection you may be forgetting.