Ford Repair: ANB light staying on, safety enhancement, antilock brake systems

Question
After reading your bio I am sure you will know this one... Our '00 Explorer ALB light stays on all the time.  Is this a major and/or costly repair?  

Thanks you!
Christine

Answer
Chris, there are two antilock brake systems used on the Explorer (rear wheel ABS, and 4-wheel ABS) but both systems have a common sensor that is probably the most likely cause of a failure... the rear axle speed sensor.
Of course, diagnostic tests should be performed with specialized tools to determine the cause, then the repair made and the code cleared and retested...
I would estimate that about $200-$250 should be adequate for the most common failure.  Your Ford/Linc/Merc dealer is best equipped to handle that, although many better-equipped independent shops could read the code and monitor the sensors.
Hope this helps you make a decision... ABS systems are a considerable safety enhancement, so I certainly recommend having it checked.
Clay