Mechanics

FULLY CHARGED BATTERY - NO POWER

1977 Chevrolet Nova • V8 2WD Automatic • 105,000 miles

The other day I started the car up and it ran fine. While letting it warm up the engine died. I turned the key to re-start it and got nothing. With a little troubleshooting I found I had no power to anything in the car. Not even headlights or horn. I checked the battery and it still has a full charge. The connection from the battery to the cables is good, tight and no corrosion. Do you think the starter is bad?

Thanks
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Corvette Bill
August 19, 2011.




The starter is not going to make the engine stall or the head lights not work.

How did you determine the battery was fully charged? Do you have a digital voltmeter and know how to use it?

Caradiodoc
Aug 19, 2011.
Yes. I checked the battery and its at 14 volts. It started fine and ran for about two minutes then cut out. Since that time there is no power to any head/tail lights, Interior lights, Horn or anything else. I also checked all the fuses and they are not blown. Any ideas?
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Tiny
Corvette Bill
Aug 19, 2011.
GM likes to use fuse link wires that tap off at the large starter terminal. I'd look there first. If you tug on them and they act like a wire, they're okay. If they act like a rubber band, they're burned open. I can't think of anything that would cause such a severe short while the engine is running to burn one open. I think it's more likely you're going to find one of them just got tired of being a fuse link and corroded apart.

You can also measure the voltage on the large output terminal on the back of the generator. If battery voltage is missing there, again, suspect those fuse links.

Caradiodoc
Aug 20, 2011.
Also look at the fuse box and wiggle the harness going into it. In the late '70s GM started using aluminum wires in some cars. When you have two different kinds of metal and an acid, such as road salt, you get "galvanic action". In other words, you have a battery and corrosion. There's brass strips and rivets in the fuse box that the aluminum wires were riveted to, and the box sat right above the driver's feet, right where road salt and water could migrate to it. I found that on a Firebird once that had intermittent tail lights. The only aluminum wires I saw were for the rear harness. To fix it, I soldered some new copper wires to the brass strips in the fuse box and ran those to the back of the car. The insulation on those wires is translucent and you can see the wire inside. Don't poke the insulation to take a voltage reading, (never an acceptable method on any wire), because moisture will get in and corrode the wire apart at that spot in a few months.

Caradiodoc
Aug 20, 2011.
Excellent info. I'll check it out on Sunday and let you know how I make out. Thanks

Tiny
Corvette Bill
Aug 20, 2011.

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