Intermittent no start
Thread Starter
Drifting
Joined: Oct 2009
Posts: 1,725
Likes: 237
From: marietta, GA
Intermittent no start
My 67 would not start this morning. Just a couple of clicks then nothing, it started on the second attempt. I let it run for a few minutes then tried it again and nothing, not even a click, no lights, horn, clock. The battery tested at 12.47 V and 14.4 when it ran. I cleaned the battery terminals even though they were clean and tight . I'm going to get my race ramps and check the connections at the starter. Before I start replacing parts I would appreciate any advice as to the problem. Thanks, Peter
Race Director
Joined: Jan 2002
Posts: 15,351
Likes: 2,724
From: Close to DC
C2 of the Year Finalist - Modified 2020
Have you checked the firewall connector for the "red wire syndrome"? The large red wire sometimes gets corroded inside and the least movement can break the connection resulting in intermittent starting. Search for this. 
Dennis
Dennis
Team Owner
Joined: Jul 2006
Posts: 22,181
Likes: 4,178
From: Kannapolis NC
The symptoms are pretty clear indicator of a battery that doesn’t have current to provide. Disconnect battery leads and connect to a known good battery. Don’t just jump battery, disconnect old one snd connect good one. Jumper cables ok. Report back.
Thread Starter
Drifting
Joined: Oct 2009
Posts: 1,725
Likes: 237
From: marietta, GA
Thank you; The battery tested at 12.6V. It's an Interstate battery 5+ years old. The car just started right up. I'm thinking if it were a bad battery it would not be able to start the car. Earlier when the car did not start, I had no crank, lights, horn or clock. Does this sound like the ignition switch?
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Team Owner
Joined: Jul 2001
Posts: 21,391
Likes: 1,011
From: Various places in Southern California.
No. As noted, the horn should be live all the time and its voltage does not run through the ignition switch.
If you have an intermittant complete dead condition (as in, everything, including horn, ignition, starter, courtesy lights stop working) it's got to be the battery itself or its connections (mainly ground).
If you have an intermittant complete dead condition (as in, everything, including horn, ignition, starter, courtesy lights stop working) it's got to be the battery itself or its connections (mainly ground).
Team Owner
Joined: Jul 2006
Posts: 22,181
Likes: 4,178
From: Kannapolis NC
You have either:
an internally defective battery (intermittent)
loose or corroded connection on the battery cable (wire to clamp) on one or both posts
negative battery terminal is loose or corroded where connected on the other end.
loose or corroded connections on the post of the starter solenoid that ties the battery voltage to the rest of the car.
A corroded connection can read good with a voltmeter, but when you try to send large starter current across the connections, it can't overcome the resistance of the connection. Your problem is within a foot or so of the starter connections and battery connections. Nothing else will cause your exact symptoms.
an internally defective battery (intermittent)
loose or corroded connection on the battery cable (wire to clamp) on one or both posts
negative battery terminal is loose or corroded where connected on the other end.
loose or corroded connections on the post of the starter solenoid that ties the battery voltage to the rest of the car.
A corroded connection can read good with a voltmeter, but when you try to send large starter current across the connections, it can't overcome the resistance of the connection. Your problem is within a foot or so of the starter connections and battery connections. Nothing else will cause your exact symptoms.
Team Owner
Joined: Jul 2006
Posts: 22,181
Likes: 4,178
From: Kannapolis NC
RE: option #4 above. Loose connections on the starter solenoid post where the battery connects, or corrosion between the wire connectors are possible . Make sure the nut is tight and clean and the ring connectors are tight and clean to the post and to the wire that attaches to them. Check to see if your fusible link at the starter is brittle or crusty, as in having been overheated.
Thread Starter
Drifting
Joined: Oct 2009
Posts: 1,725
Likes: 237
From: marietta, GA
I appreciate all your help. I did clean up the battery terminals and today I am going to check the battery connections at the starter. I'll remove and clean them and probably get a fresh battery since the one I have is going on 6 years old.
Le Mans Master
Joined: Feb 2012
Posts: 5,371
Likes: 2,878
From: Western Massachusetts
2024 C2 of the Year Finalist - Unmodified
2023 C2 of the Year Finalist - Unmodified
2019 C2 of Year Finalist (stock)
2015 C2 of the Year Finalist
6 year old battery with an occasional no crank? 65GGvert's advice is to be followed. If the problem remains, you have a battery with an internal short or open that fixes itself with temperature or current flow. At year 6 a car battery owes you nothing. No rhyme or reason either. The AC Delco in my 65 396 is 11 years old and still works. I've had Interstate and NAPA batteries go only 4 years. Buying and installing a battery can be a trip to the casino.
When replacing a battery it is a good idea to check your charging system. Make sure you are between 13.8 and 14.2 volts or very close at high revs, headlamps on. Often mechanical regulators will pit their contacts and stick which can overcharge and shorten battery life considerably.
Your dash battery gauge will not inform you of overcharging.
Dan
When replacing a battery it is a good idea to check your charging system. Make sure you are between 13.8 and 14.2 volts or very close at high revs, headlamps on. Often mechanical regulators will pit their contacts and stick which can overcharge and shorten battery life considerably.
Your dash battery gauge will not inform you of overcharging.
Dan
Thread Starter
Drifting
Joined: Oct 2009
Posts: 1,725
Likes: 237
From: marietta, GA
UPDATE; To solve the intermittent no start, I purchased a new AC Delco group 24 battery from my local dealer and ordered new battery cables from ZIP. I'm not quite sure why, but the spring clip on the cable will not fit over the posts. My old cables seemed to be in good shape so I cleaned them up and will use them.