Hello,

I need some wisdom from the community. Had a battery that was dying in my 96 LT1 CE (SYS flashing intermittently, OBD II scan confirmed). Went and bought a new Duralast battery removed old and installed new. Now I have idiot lights on the center console and around the CCM but no dome lights or CCM. Turning the key results in nothing, except a few more lights around the CCM. Everything went as easily as can be expected for changing a battery in a C4 (wow). I hear things electrically buzzing under the hood and what sounds to be the fuel pump, but when the key is turned…nothing. I have a quick disconnect on the negative post that I disconnected before I started removing items and didn’t contact the positive post to any metal. I’m confused, does anyone have any advice, or can tell me if I screwed up something?

Thanks in advance

Shotgunwilly

 

What is the battery voltage as measured at the terminals? What is the voltage showing on the digital display.

First guess is that the battery you bought is discharged.

 

Reading 12.65 volts on the new battery. Old one was reading 14 volts on the CCM, but battery was 'chugging' when started. Asked my mechanic about the alternator when he had the OBD reader hooked up, said it appeared fine.

 

12.65 volts on a good battery is about 60% of full charge which should operate your car just fine. When the battery is connected and the ign in run, what does the battery voltage read at the battery terminals. It should still read 12.65 volts or very close to that. Buzzing noises on battery hookup indicates a very low battery voltage, like 10 volts. Test voltmeters draw extremely low current (microamps) and defective batteries can deliver microamps and measure 12.65 volts. You should barely be able to see the battery voltage drop (.05 volts or lower) when you turn on your headlights. If your new battery holds 12.65 volts with the headlights on, then the battery is not suspect. The dash voltmeter will not read battery voltage correctly unless the engine is running and the alternator is maintaining 13.3 - 14.7 volts across the battery. With the headlights on, measure the voltage on the cigarette lighter socket. If lower than 12.0 volts, I would suspect a defective fusible link or a blown fuse or poor connection on one of the fuses in the fuse block next to the battery that supplies power to the ign switch.

 

I'm not sure but I believe your fuel pump is in the gas tank. Maybe your quick disconnect on your negative post isn't reconnecting good enough. Just a thought.

 

I'd remove the quick disconnect. Most are crap anyway. Furthermore, I don't see any need when all you have to do is use a box wrench and give a half dozen twists. Hard connect it to that battery and give it a crank. Good luck.
Mike

 

Could be the QD is a problem. Remove it and see if that helps. But look at the metal rings inside the cable ends. You could have some corrosion built up in there which could keep from making a good contact to the battery. The studs in the cable end can be removed by pushing out from the threaded end. PITA to do but it might be worth checking.

Also check the other end of the negative cable to make sure it's tightly attached to the frame and free of corrosion. Same with the positive cable at the starter.

That clicking you hear may be a relay that is trying to work but can't get enough amperage. The 12.6v is OK for voltage but the starter needs lots of amps to get it to work. Something is not allowing higher amperage to pass thru.

 

Well upon removing the battery I discovered the problem, secondary wire from the post was not reinstalled to the underhood fuse block when I put the battery in. Life is good once again. Thanks for the help.

 

Welcome to the world of Corvette repair. Most jobs include at least 1 operator screwup.

 

12.65 is a fully charged battery. Where do you get 65%?