Troubleshooting experts, enter.
 

This happened to me the other day so I figured I would try out everyone’s troubleshooting skills.
Background- 65 Corvette, everything is brand new from the wiring harness’ to the lugs nuts. The battery is one of those reproduction batteries that has the Odyssey AGM inside of it. I’m using a knob type battery disconnect.
Situation- I fire the car up in the A.M. and head to a car show – everything is normal
Park the car at the show and disconnect the battery.
6 hours later, connect battery and try to start it. The solenoid clicks once and then everything is dead, not even a dome light.

Tell me what you’d try and I’ll give you more info. Good luck.:cheers:

sounds like a bad spot on the starter. first wiggle battery connections. if connections appear okay tap starter with hammer. try to start and if still no luck use screwdriver to jumper solenoid and starter.

The knob type battery disconnect probably was at fault. I'm not a big fan of the AGM batteries either.

Bad/loose ground to starter...?

Everything is tight. Remember, even the dome light is out.

I removed the disconnect and put the cable directly to the battery. No change. Odyssey Batteries are used extensively in the airline industry as well as in nuclear subs. Very highly rated.

Everything is tight.

Me and my buddies are really scratching our heads now. I get a ride home and come back with tools, jumper cables, an extra battery and a volt meter. The first thing I check is battery voltage-12.9 volts indicating a fully charged battery.

where do you go from here?????

Check your connector at the firewall. Mine did this when I first got it. Believe only place I would have power was at the horn. Everything else was dead. If I put upward pressure on the connector it would "fire up".

My normal check in such a situation is to put a voltmeter across the battery....I expect to see 11.8-12.5V or thereabouts. If not the battery is suspect. Then take the same measurement while somebody cranks the motor. I expect to see a voltage drop to 9.5-10.2V or thereabouts. If there is NO significant drop then my first suspect is corrosion or loose/bad connections. If the drop is much greater than that I have found the battery may be bad...bad cell or what have you.

Of course, I'm betting is none of the obvious problems or Jim wouldn't be teasing us. Indeed a unique problem to C2s (and my '67 Chevelle) is the firewall connections for the major circuits. It takes almost nothing, current wise, to light a dome light so that is a key clue to what is going on IMO.

Electric connection at firewall..? Happened to me once, a clean up and a wiggle and good to go.

I also had a bad firewall connection once. Took FOREVER to find it. If that connection is loose you will have exactly what you describe..power at the battery and nothing on the interior.

Im no corvette expert but maybe this helps. I had that happen on my 1969 chevelle. that car would even shut down driving for no reason. it had aftermarket gauges in it. PO ran everything through the amp meter. everything except the main starter and ground leads. the wires were just loose on the quage studs. took a while to find it. not sure how your car is wired. I would hook up your volt meter to the - on the battery and look for voltage at the starter, alt, fuses, ign switch etc until you find no power. a test light would be easier to see.

Get out an ohmeter and start measuring where it gets lost.

Have had an auto battery many years ago that measured good (indicated fully charged), but would fail internally (internal open connection). As soon as a high load was needed (starter), it would open up and no voltage was indicated at the battery posts.

Good luck,
Plasticman

Update:

New harness' and connection at firewall is tight.
Remember - 12.9 volts at the battery. I check voltage at alt. battery terminal, solenoid terminal and on the engine side of the firewall connector - 12.9 volts.
Open the door and check the dome light -it's out. Checked for voltage at the fuse box- zero.

Jim

if you take the disconnect out of your circuit do you then get a dome light?


Please clarify where your disconnect is located in the circuit

That's the first thing I did = no change. It was on the neg. cable at the battery

Hi, I have experienced first hand in the past loose connections of the studs on the solenoid. You need to take off the starter solenoid wires and make sure the studs are secure in the solenoid itself. Put a wrench on them and see if they are loose.

EJ

Everything is tight.

Clean your battery terminals and the associated cables, then check the attachments points for the cables at the ground,and solenoid.


Can you short across the solenoid and make anything happen? As in trying to make motor turn over, like you are stealing the car? Any sparks? if you get sparks, you have power to to both ends of the starter, and the problem is in the wiring harness, fusible link, etc. If you don't get sparks or motro turn over, one of your bat cables is bad.

Edit; you could just have bad battery, and it may read 12V, but isn't putting out any amps at any load. Unlikely, but possible. Typically a situation witha bad battery will leta dome light come on, but then as soon as you try and start the car, everything goes dead.

Doug

If I had good power and good grounds I would get out the wire diagram and see where dome light power came from, see if there was anything in common to the start circuit like firewall connection or ignition switch.

You forgot to turn the green knob on your battery disconnect or it was not tight enough.

All good suggestions. No fusible link on a 65 and it has a shield around the solenoid so it was hard enough to check for voltage there, 12.9 volts but impossible to use a screwdriver to short it out. Battery cable and battery are brand new, clean and tight.
Trust me, I'm surrounded by guys that have been building hot rods for 40+ years and we're all scratching their heads.:crazy2: