C7 battery charger question
Thread Starter
Safety Car
Joined: Jan 2014
Posts: 4,496
Likes: 856
From: Walhalla South Carolina
C7 battery charger question
My Corvette battery charger just started the orange charging light flashing continously. It's a us3300 Corvette model 1051. Disconnected it several times, same reaction. Is it battery or charger? Thanks
Drifting
Joined: Sep 2004
Posts: 1,470
Likes: 442
Got a volt meter? See how close to 12.66 battery is. Or try it on another vehicle. I have a cheapo Bat tender for my lawn tractors and on my Cub it was giving wacky readings but on my Zero Turn showed correct. Turned out to be the battery itself. These lawn tractor batteries won't last as long as a car 12v even with a good charging system. Or go buy a cheapo bat tender from Wal-Mart for about 20-25 dollars and have a backup. They do they same thing the high dollar tenders do without a Corvette emblem.
Thread Starter
Safety Car
Joined: Jan 2014
Posts: 4,496
Likes: 856
From: Walhalla South Carolina
Got a volt meter? See how close to 12.66 battery is. Or try it on another vehicle. I have a cheapo Bat tender for my lawn tractors and on my Cub it was giving wacky readings but on my Zero Turn showed correct. Turned out to be the battery itself. These lawn tractor batteries won't last as long as a car 12v even with a good charging system. Or go buy a cheapo bat tender from Wal-Mart for about 20-25 dollars and have a backup. They do they same thing the high dollar tenders do without a Corvette emblem.
Advanced
Joined: Jul 2021
Posts: 95
Likes: 39
From: New Hartford, NY
Had the exact same problem. Purchased a replacement "cigarette lighter" plug on Amazon, spliced it in and the problem is gone! I understand that the "factory" plug is of inferior quality.
Thread Starter
Safety Car
Joined: Jan 2014
Posts: 4,496
Likes: 856
From: Walhalla South Carolina
Had the exact same problem. Purchased a replacement "cigarette lighter" plug on Amazon, spliced it in and the problem is gone! I understand that the "factory" plug is of inferior quality.
https://www.amazon.com/AAOTOKK-Cigar...5cRAEY1ATzsuqb
https://www.amazon.com/AAOTOKK-Cigar...5cRAEY1ATzsuqb
Drifting
Joined: Apr 2018
Posts: 1,323
Likes: 928
From: Burnt Hills NY
Before buying anything, rotate and push on the plug connector (male) to get a better connection. This works for me. Also make sure you are using the 12V outlet above the battery in the back. That is the only one that will work for charging.
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Advanced
Joined: Jul 2021
Posts: 95
Likes: 39
From: New Hartford, NY
Yep, it was the male plug that was bad and I've heard that I'm not the only one with the issue. I just think it's not really compatible with the female socket in the hatch area. I used my Vette charger with the lighter plug on another vehicle and my UTV, no problems. Used my Battery Tender with the lighter plug on the Vette, no problems. Changed the Vette charger to the plug I got on Amazon (same as the Battery Tender plug) and have had successful charging since October'24. And there's only two wires, one red and one black. You can't screw up splicing it in, just be sure you've got a good connection.
Last edited by Undatakr; Jan 31, 2025 at 04:00 PM. Reason: additional information
Thread Starter
Safety Car
Joined: Jan 2014
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From: Walhalla South Carolina
I have had to do as you say from time to time as well. Seems like a flimsy component. Thanks for responding.
Tech Contributor
Joined: Oct 1999
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From: Charlotte, NC (formerly Endicott, NY)
Sometimes unplugging and reconnecting the AC power plug will resolve the blinking light other times you may need to wiggle the male plug in the socket to get better contact or just replace the plug and maybe the socket.
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My thoughts are it is a bad connection on the battery tender. Mine does that occasionally and when I turn the plug in the hatch receptacle it works fine again.
Melting Slicks
Joined: Feb 2018
Posts: 2,184
Likes: 1,050
From: North Texas
Basically the CTEK's plug is made for European cars and to make it work some what for American cars they added an adaptor but it still doesn't work well.
Thats just 'one' of their not so well designs on this charger.
Thats just 'one' of their not so well designs on this charger.
Melting Slicks
Joined: Feb 2018
Posts: 2,184
Likes: 1,050
From: North Texas
Even though you hook up the wires backwards the charger knows and won't start the charging cycle.
Usually gives a reverse connection code.
But simply connect black to black and red to red.
Usually gives a reverse connection code.
But simply connect black to black and red to red.
Race Director
Joined: Mar 2001
Posts: 19,965
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From: Bonneville Salt Flats
I've a bunch of vehicles and three different brands of tender (plus, one real battery-charger... not the same thing, btw); and, what I find with the GM/C7 plug-in is that it helps to always twist the plug back and forth a couple times whenever plugging it into the car socket. I've never had an issue with these things doing so . All the best. 
