[Forker]

The car is a 1972 Challenger with the original low compression 340. When I put it into storage last November, the car ran perfect. Over the winter, I pulled the battery (which was nearly new), and kept it indoors. Voltage remained at 12.7 V without the use of a tender.

Earlier today, I put the battery back in the car, and attempted to start it. The clock, headlights, and accessories all work fine until I attempt to actually crank. It sounds like the starter wants to to turn over, but before it can (less than a second after turning the ignition switch to start) all electric power is lost. Briefly disconnecting/reconnecting the negative battery lead resets everything, but the same problems persist.

Before I proceed down the path of diagnosis by repair (beginning with the starter solenoid?), I'd *really* appreciate any advice you all could offer.

Thanks!!!

[Eddie]

The first thing I would try is a new or freshly charged battery. But before you crank it over tap the starter motor with a hammer, sharply, place a rag/piece of paper cardboard on it so you dont scratch your starter on your beautiful car!!!

[Goldenblack440]

Yes, i agree with Eddie, it sounds like the battery has lost its guts. Don't forget any battery can give an appearance of its full charge in voltage, but when it comes time to deliver the guts or cranking power, it can fall over. The worst thing batteries hate is sitting around doing nothing. Also, i would pull off your terminal leads and get a Rat tail file and give the inside of the terminal leads a good scrape. They should be lead or bronze. Do the same with a fresh battery. Also make sure the connection to the body from the earth battery lead is shiny metal on both surfaces, AS WELL as the body to engine earth strap which should be from firewall to one of the heads. If you have not got one of these, i'd suggest putting one on, otherwise the engine itself relies on getting an earth through less direct paths.

finally, give the starter motor a few taps and give the starter solenoid a few taps as well.

[Moparman1972]

I would tend to think that battery is dead at 12.7 volts. It should have over 13 volts when you test it, to be able to crank the car.

Charge the battery up and just clean the terminals before getting into checking grounds and all sorts of trouble.

[dave-r]

I would tend to think that battery is dead at 12.7 volts. It should have over 13 volts when you test it, to be able to crank the car.

Mmm. I would tend not to agree with that. But you need to remove the surface charge before you measure it.

If the battery has been charged within the previous 24 hrs, the surface charge must be removed before any measurement is taken. This can be easily done by turning on the headlights for 2 or 3 minutes. THEN the voltmeter can be connected to the battery terminals and the exact voltage measured.

<TABLE><TR><TD>STATE OF CHARGE</TD><TD>VOLTAGE </TD></TR><TR><TD>100%</TD><TD>12.60 </TD></TR><TR><TD>75%</TD><TD>12.40 </TD></TR><TR><TD>50%</TD><TD>12.20 </TD></TR><TR><TD>25%</TD><TD>12.00 </TD></TR><TR><TD>0%</TD><TD>11.80</TD></TR></TABLE>

[Goldenblack440]

I would tend to think that battery is dead at 12.7 volts. It should have over 13 volts when you test it, to be able to crank the car.

Charge the battery up and just clean the terminals before getting into checking grounds and all sorts of trouble.

That is not correct - voltage and cranking capacity are lightly related but not interchangeable as a measure. A battery is charged by the alt system at about 13.6 to 14.2 Volts, but will fall back to mid 12's when stationary and when has been sitting for a while or has had a light load applied. A battery can have a full voltage "shell" but not be able to deliver any substantial cranking power. This is the measure of a healthy battery, as i took pains to explain in the first reply.

[Moparman1972]

My mistake