Wiring help please...

[Chevelle454]

Okay, here's the deal...

The car is a 1984 Chevy Caprice.

Last night, I was pulling out of the parking lot at work(kinda given it some gas), when all my lights shut off. The headlights, taillights, interior lights, gauge cluster lights, hood and trunk lights, radio, horn, and the HI setting on the fan speed all stopped working. The brake lights and turn signals were all that was still working.

Tonight, I started testing the fuse box, and it seems that parts of it have no power where they should, with the key in any position. I took a jumper wire and put it from a 12V source on the car to a space in the fuse panel labeled "BAT". Everything worked on the car after I did that.

I tested things out, and everything seemed to work alright. I turned on the headlights, radio, then turned the fan on high and I heard a pop from under the dash. Now the headlights and taillights don't work anymore, but everything else still does with that jumper wire in place.

It appears that all the fuses in the fuse box are good. I can't find any fusible links. I can't get the lights to come on now at all.

Any ideas as to what I can try next? I am trying to sell this car and that will be very hard to do if things like the headlights don't work...

Thanks in advance...