Warning beeper that never stops, even when key OFF and out.

I am repairing a Ford F150, 06/98, 4X4 that was hit by a tree dead center pushing the core support back and damaging the fan only a little. We stripped all the sheet metal to try to start it (which it won't. But that's for another day). Our problem is a beeper that goes off every few seconds with the doors closed and the key out until it kills the battery. The sound comes from the passenger kick panel near the fuel pump reset switch (which we reset after the crash. But the pump still doen't run). This is my first trip to your site.I hope you can help. Mike in Ohio