Freak Electrical Incident

Alright, I've got a really weird problem, and I'm not sure how to go about fixing it.

I was driving my 1994 XJ Sport this morning when I flipped on the AC, and the radio turned off for a second. It came back on after awhile, so I figure, ok.

My dad borrowed the car earlier this evening to go to Dollar General nearby, and he came back about an hour later saying that he couldn't get it to start. He mentioned something about the battery terminal being loose, and if he shook it around, then he could get the lights to come on, but not to start the car.

We went back to it later this evening to try and get it to start again. We tried tightening up the battery terminals...nothing. There was no electric in the car, except to power that little buzzer, and only faintly. For some reason or another, my dad realized that the brake didn't need to be applied in order to shift from park. He moved the shifter back and forth a few times, and, viola, everything turned on again.

Is there any logical explanation for this? Maybe a short? Where should I look?

allmost sounds like the neutral saftey switch. but not so much. something is def. going to ground.

Does anyone know where I should start looking, or how I should look to see if something's going to ground?

Well the NSS don't turn all the power off. You need to remove and clean those battery terminals, don't just tighten them.

and check the grounds. Make sure the cables themselves are in good condition and not corroded under the insulation.