1994 ford taurus ABS Light/Buzzing/Vibrating...

I have a 1994 for taurus wagon. Yesterday when I was at a stop light, the car started vibrating and started making a buzzing sound. The brake became hard, and has some push back. I can stop, but when I tap the brake it's like it is over compensating and it stops quick and hard. I tried to see if it would reset by checking fuzes, and disconnecting the negative power from the battery. After hooking up the negative again, it just keeps buzzing. Even after the car is turned off.

Any ideas what is going on? How can I remedy this, and anyone know if this, if not easily fixed, how much will a repair cost?

Thanks.
-T-

It sounds like your ABS system is engaging. You're probably going to need to find a professional scan tool that can access the ABS system and monitor the various ABS parameters real time to see what sensor is reading wrong and causing the ABS to engage.

-Rod