Greetings all.

My wife has a 2001 Ford Explorer XLT.
If the driver's door is open and the key is not in the ignition, there is a constant fast-paced beeping.
Shut the door, and it stops.

Sometimes when we first open the door to get in, it doesn't beep, but as soon as you start to sit on the seat, it starts beeping.

Could it be a bad ignition key sensor in the key tumbler on the steering column?
If so, could I disable it, or replace it fairly easily?

Any other suggestions?

Thanks!

Rapid beeping sounds like the "headlight still on" alert.....

If it was somehow still sensing the key, it would be a slower beep...

I went and tested it, and with the headlights on or off, the speed does not increase.
It sounds exactly like when I leave the keys in the ignition of my F150, turn off the engine, and open the driver door.