My 2001 For Windstar Vans break light comes on occasionally when backing up in reverse. What is wrong?

Hello, You have debris in the rear brake assembly. The rear wheels have 2 sets of brakes. There are service brakes and Emergency brakes. The sensors that count the wheel revolutions for the ABS system get blinded by loose debris when the Emergency brake pads fall apart.

When you back up, the loose debris shifts from where it was packed going forward and falls in front of the sensors when you go in reverse. You need to have the rear Emergency brakes checked.

I hope my solution is very helpful to you.

Might be a loose wire