68 Battery Drain
Thread Starter
Advanced
Joined: Apr 2004
Posts: 95
Likes: 10
From: Osceola IA
68 Battery Drain
I have a friend who is working on a 68 Corvette, 327 with AC. He is trying to troubleshoot an issue whereas the battery is apparently being drained. This particular Vette was in storage for a number of years and the following problems have surfaced:
Headlights will not open. There is also a problem with the brakes but really don’t think this is associated with the battery drain issue. The battery is a new replacement. The alternator and volatage regulator have also just been replaced but the battery continues to drain. Fuses have been pulled in an effort to stop the drain and hopefully reveal the system / component related to the cause of this drain. No joy as of yet!
Have any of you experienced a similar occurrence? If so, we would be most appreciative if you would please provide any related causes. Or perhaps you may have some troubleshooting guidance that you could share in an effort to help us resolve this mystery.
Please be assured your contributions are sincerely appreciated!!
Thank you in advance!
Frank Jones
66 Coupe
Headlights will not open. There is also a problem with the brakes but really don’t think this is associated with the battery drain issue. The battery is a new replacement. The alternator and volatage regulator have also just been replaced but the battery continues to drain. Fuses have been pulled in an effort to stop the drain and hopefully reveal the system / component related to the cause of this drain. No joy as of yet!
Have any of you experienced a similar occurrence? If so, we would be most appreciative if you would please provide any related causes. Or perhaps you may have some troubleshooting guidance that you could share in an effort to help us resolve this mystery.
Please be assured your contributions are sincerely appreciated!!
Thank you in advance!
Frank Jones
66 Coupe
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,231
Likes: 9,371
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
disconnect the wires to the wiper there is a 3 prong straight blade and a 3 prong square. Most likely it is the wiper override under the dash is turned so that is activated. EVerytime you bump it it will be on draining the power. It might stop if you pull the wiper fuse but since its a 68, all bets are off on that.
After that he will have to disconnect the positive wire from the battery and put a multimeter in line set to amps. It will show the power travelling through the meter. Then start unplugging all electrical things like light bulbs even if they are not lit. I helped a guy down in NJ and he had a passenger side courtesy bulb that was draing his battery. It was not lit
After that he will have to disconnect the positive wire from the battery and put a multimeter in line set to amps. It will show the power travelling through the meter. Then start unplugging all electrical things like light bulbs even if they are not lit. I helped a guy down in NJ and he had a passenger side courtesy bulb that was draing his battery. It was not lit
Instructor
Joined: Nov 2020
Posts: 143
Likes: 28
From: Colorado Springs
My experience
Had a similar issue a while back. Turned out to be the horn relay. Contacts were so corroded that they stuck closed but resistance was so high the horn would not sound. New relay fixed it
Thread Starter
Advanced
Joined: Apr 2004
Posts: 95
Likes: 10
From: Osceola IA
I’ve printed your response and am on my way to deliver it to the mechanic at his shop. Hope this will be the culprit!
Thank you for your response and guidance.
Much appreciated!
Frank
Thank you for your response and guidance.
Much appreciated!
Frank
Team Owner
Joined: Jul 2004
Posts: 40,417
Likes: 792
From: Redondo Beach, California
For my 68, I eventually found that the battery drain was caused by the windshield wiper motor spontaneously turning on. Have no idea of the actual cause. This would happen with the car garaged. With no vacuum, the windshield wiper door would not open and the blades would rise slightly, hit the underside of the door, jam and drain the battery. Since this was a random occurrence, trouble shooting was difficult. To eliminate this a cause, just unplug the windshield wiper motor. My solution was to convert to a 69 windshield wiper system. Not an easy conversion.
For a 69, the drain source was the little light bulb in the center rear storage compartment. I'm referring to the three storage compartment doors behind the drivers and pasengers seat. The center one functions as the glove box. The little light bulb was always on.
For a 69, the drain source was the little light bulb in the center rear storage compartment. I'm referring to the three storage compartment doors behind the drivers and pasengers seat. The center one functions as the glove box. The little light bulb was always on.
Last edited by 68/70Vette; Aug 31, 2021 at 02:54 PM.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
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
Thread Starter
Advanced
Joined: Apr 2004
Posts: 95
Likes: 10
From: Osceola IA
We are happy to report that when we disconnected the 3 & 4 prong connectors at the wiper motor, the amp meter indicator went down to zero. We also found one brown associated lead that had chaffed in two and another lead arching against the ignition shield / cover assembly directly in front of the wiper motor. With these discoveries, Tom (mechanic) advised that he would address the wires and suspect wiper motor. Hopefully this will prove out to be the cure for the battery drain issue. I will follow up with Tom later in the week and check progress of repairs.
I want than you for your recommended trouble shooting guidance.
I also want to express our sincere appreciation for all the others who contributed to this effort with their suggestions and time.
This forum rocks! And you folks are the ones that count for 5he numerous success’s.
Thank you for making these electrical anomalies manageable for us that are a bit challenged with the electrical issues.
Sincerely
Frank Jones
I want than you for your recommended trouble shooting guidance.
I also want to express our sincere appreciation for all the others who contributed to this effort with their suggestions and time.
This forum rocks! And you folks are the ones that count for 5he numerous success’s.
Thank you for making these electrical anomalies manageable for us that are a bit challenged with the electrical issues.
Sincerely
Frank Jones
Thread Starter
Advanced
Joined: Apr 2004
Posts: 95
Likes: 10
From: Osceola IA
No! I don’t think Tom is aware of that switch nor was I. I will head out to his shop in the morning and will make a copy of your email.
Thank you! That is a very significant point, I must say.
Thank you! That is a very significant point, I must say.
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,231
Likes: 9,371
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
read post 3...