Where is the BCM located?

Ford calls this a smart junction box and it is behind the dash.

Here is a guide that will help with replacing BCMs:

https://www.2carpros.com/articles/how-to-replace-a-bcm-body-control-module

While your will be slightly different, the process is basically the same.

Please see the info below on how to replace this from the manual and let us know if you have other questions. Thanks

I have a 1997 Taurus GL with 110000 miles. Recently I started having a problem where the door ajar light stays on with all of the doors shut tightly. Also the power windows intermittently work and dont work. When they are having problems, it also feels like there is no power steering. If i put the car in Park or Neutral, they work fine, but if it is in drive or reverse they act up. This happens when either at a stand-still or when moving. Also, the seatbelt light flashes on and off with the seatbelt engaged. It sounds like a relay "clicking" when this is happening.
Is it the BCM?

I would check the mlps sensor which is attached to the top of the trans, this sensor can cause a lot of weird stuff when it malfunctions.. any engine codes??? the door situation could be a switch that's acting up, some squirt wd40 or some type of electrical contact cleaner in the doors to combat sticking switches..