[i82much]

Last night I took my car out for the first drive of the season. Started up just fine. Stopped to fill up, and the car wouldn't start - turned the key and nothing. Let it sit for a few minutes and it started up fine.

When I got home, I put a voltage meter on the battery. With the ignition key off, it read about 12.6 volts with the red test lead touching the lead positive battery post. Driver's side door left open and the interior bulb was really dim.

I move the test lead to the nut that holds the terminal onto the positive post, and it reads around 3 volts. Same result (3 volts) at the other end of the positive battery cable where it connects to the Ford-style solenoid.

The battery is seven years old, so I should probably replace it anyway. But I don't get why the lead post would read over 12 volts when it is only 3 volts right at the battery terminal nut and at the solenoid. I guess it could be a corroded terminal, but the terminal looks fine and I can't understand why the car cooling off would make a difference?

Interesting note, this car does have electric fans. So maybe the car cooled off enough to drop below the threshold where the fans turn on, in between when I first tried to start the car at the gas station and a few minutes later and I got it started. But that doesn't explain the difference between the reading at the post vs. the reading at the terminal?