I have a 1988 Delta 88, which has been mainly sitting in my back yard the
last few months. I check fluids and the start it up and run it about once a
week for 15 minutes. Last week, it wouldn't turn over at all. No clicking or
even attempting a start. I have one of those backpack jump starters. If I
connect that to the battery and let it charge the Olds battery for about a
minute, the car starts, all lights are strong right away. In fact there's
strong headlights as soon as I put the jump starter on, after charging a few
seconds, even before I start the car. I made several attempts, after
jumping, letting the car idle and hopefully charge anywhere from 10 to 30
minutes. As soon as I turn the ignition off, the car will not restart. No
headlights, dome light very dim, power locks may or may not lightly click,
but won't lock the car. As soon as I jump it again, everything is fine until
I shut the car off again. I didn't try driving it in this state. I don't
have any tools or battery wrenches here, and no voltage meter, any way of
telling from the symptoms if it's the battery, alternator, or solenoid? I do
have an Escort radar detector that also can give you the voltage, and when
running seemed  to be 14 volts, but once the car is shut off will say "LOW"
or will not power up at all. Thanks in advance.