Ted,
And, fortunately, everyone has one of those in their garage

 

At 71, I used my picker to install this TKX on an engine... Hard to believe 50 years ago I benched pressed em up into the bellhousing laying underneath the car many many times....

 

Ok, I wish I could say I made progress today, but all I really accomplished was getting some good experience working on this old gem.
I'd suggest avoiding the Interstate Group 24 from Costco. As I mentioned, it has a built in carry strap. Of course the top battery mount can't have a strap under it, so after I got the battery in place I took a pair of tin snips and cut off the strap. Of course the top battery mount still wouldn't fit because the battery is wider at the top for the strap supports. So I pulled the battery back out. I decided not to use the battery strap I picked up today as it really dinged up the battery posts on my old battery. So it was a challenge getting that battery back out. I hate to say it, but I just took an oscillating cutter and very carefully cut those plastic strap supports off of the new battery. It was quick and turned out to be not as ugly as I thought it might. I put the battery back in, again without the lift strap and hooked it up, reinstalled the surge tank, added coolant and hit the key.
No change. I'm ok with that, as my old battery was dated 02/2020, so I got the good out of it.
Did I mention how blessed I feel to finally have a car lift?
I went ahead and pulled the starter and installed a new one. I've always done that on my back, so this went a lot better than the battery fiasco.
But still, no change.
So with a fresh battery, it's just the same. And I want to be clear that the ammeter pegs at -40 as soon as I turn the key to the on position. It stays the same if I turn it farther to the start position, but I want to clear up that it pegs on the first click of the ignition switch.
So I'm beat, and the wife just brought a cocktail out to the garage, and tomorrow our club has a parade - now we'll be in the C5 - and then it's Mother's Day, so I've got acouple days to let my body recover, lol.
I'd like to add that my wiring harness from the firewall out is nearly new, for what that's worth.
I think I've eliminated a couple of possibilities, but I missed the fixing the problem.
So - happy Friday night everyone, and does anyone have any suggestions about where I should check next?

 

See post #3.

Live well,

SJW

 

It you end up having to replace the battery, I think there may be a better alternative to a group 34 battery. If I were you, I'd get one of the new Lithium batteries with the built in charging management system. This is an electronic system built into the battery that will make it fully compatible with the standard charging system on your Corvette. The big advantage? The lithium replacement will weigh between 16-20 lbs. vs. 50-60 for a standard lead/acid battery. Makes a big difference for us older gentlemen. These newer Lithium batteries are designed specifically to be used in older cars, and as such, pose no significant hazard as is rumored. In addition, they last longer and provide more power than a conventional battery. The one big downside is that they lose significant power at below freezing temperatures. The way these cars are used and stored, that should not be a problem. I live north of Brainerd, Minnesota, and I doubt that my car has seen temperatures below 60 degrees any time in the last 50 years.

Technology is constantly advancing.

 

It seems you have a short in the wiring from the ignition switch to the engine compartment. It could be in the ignition switch as there have been several threads here on the forum on the 65 ignition switch failures.
Your short occurs upon turning the switch to the ON position as well as in the START position. Assuming it does not deflect in the OFF position? Does it also deflect in the ACC position?
The battery gauge does not go thru the ignition switch, thus if it does not deflect to -40 in the off position, it is either in the switch or beyond.
To troubleshoot it safely, I would disconnect the battery and perform a visual inspection of the wiring. The purple and pink wires to the starter are known to short out to the exhaust system if not properly trained / routed. Also inspect all wiring to the ballast resistor and coil. Do you have the stock points system or an electronic ignition?
I would then pull the ignition switch and test it for continuity and look at the connector for evidence of overheating.
​​​​​​​

 

My bet is on the starter.
I had a 65 with the same symptoms and I could take a piece of wood and a hammer, Have someone turn the key to start and stick the wood down to the top of the starter, peck it with a hammer to vibrate it and it would start right up. A new starter solenoid fixed mine.

 

Whatever you do DON'T LEAVE THE BATTERY CONNECTED UNLESS YOU ARE THERE . Good luck. It's a dead short.

 

Have you tried to turn over the engine manually to make sure its isn't broken??

 

If it pegs -40 in the ON position, not the START position, you have a dead short well upstream of the starter. The starter doesn't get any juice until you go to START, so don't worry about wires to the starter. Look at your ignition switch or the wire to the ballast resister. If it pegs negative in the ACC position, forget the ballast resister and check the wire to the fuse box.

 

It actually sounds like your engine is locked, and the starter solenoid is stuck in the engaged position.
I hope you find a simpler explanation, like maybe a shorted solenoid winding at the starter.

 

If the solenoid were stuck in the engaged position, the starter would be getting juice regardless of key position. If the engine was seized, either the starter would fry, the wires would melt or the battery would die.

 

Follow his instructions very carefully...............IMO the best diagnostic electrical poster on our forum. begee22

 

Thanks everyone.
The battery has already been replaced, and is disconnected via a lever type battery disconnect.
The starter and solenoid have been replaced with new ones as well.
The engine is not locked up.
The solenoid does not engage when I turn the key to the start position. The ammeter does not move from -40 (pegged) when I move the ignition switch from on to start.
The 65 is up on the lift right now, and I've snuck away from Mother's Day festivities to post, lol.
I'll have time to do a couple of checks tomorrow that have been suggested -
What does the ammeter gauge do with the key in the accessory position.
And the other check is - what is the voltage to the starter when the ignition is turned to the start position. Will I just check the battery post on the starter and ground for that?
Again - Many thanks everyone!

 

What dmlParker says is usually true. If the solenoid hangs in the engaged position, it continues to crank without the key being in the start position. My thought was that when you said it almost cranked then didn't respond was it stuck and burned something up in the solenoid. Probably not.The fact that it does not peg in the run position, but does in the start position still sounds to me like the starter solenoid is completely frozen. I would try the banging on a piece of wood with the hammer trick I spoke of or just take the starter off and test it. The only thing that makes sense is when you turn it to start all the current is going through the solenoid, but not moving it.

 

Additional note: the battery gauge works even with the key in the off position so if you had a short in the wiring beyond the starter, it would still show a discharge even with the key off.

 

If all accessories are off, the ammeter should not deflect when the key is turned to the "Accessory" position.

You should always see battery voltage at large post on the solenoid, which has the large cable from the battery connected to it. Nominally, 12.6 volts DC with a charged battery.

Neither of the small posts on the solenoid should have any voltage present on them when the key is in the "Off" position.

When the key is turned to "Start" position, battery voltage should appear at the solenoid's "S" post. And if the solenoid is functioning properly, its internal contacts should connect battery voltage to the strap that feeds into the starter housing, and to the "R" post on the solenoid. This should energize the starter, and also pass battery voltage to the + post on the ignition coil to generate a hotter spark to help start the engine.

All of the above presume the system is in working order, and all measurements are DC voltage measurements with one probe of the meter connected to chassis ground, and the other used to probe the points of interest.

Live well,

SJW

 

The battery gauge will show movement of current in the system, both charge and discharge with the key in ANY position. It works as SJW said in any key position if wired properly. The fact that yours does not show discharge at -40 until you turn the key to start indicates that your problem is in the start circuit, number one suspect being solenoid, number two being starter.

 

If this gif doesn't play for you, save it and right click on open with internet explorer, or your browser

 

From reading this thread I believe the OP is stating that the gauge shows a -40 discharge with the key turned to the ON (RUN) position; before even going to START. Would this not indicate a problem in the primary circuit? Or an ACC? See post #30