The Electronic Automatic Temperature Control (EATC) does not use the standard blower motor resistor. It instead uses a solid state motor controller with PWM and a transistor to adjust fan speed. If you're lucky, the problem will be a faulty blower motor. Maybe it required the full current of high speed to get it going earlier and now it's completely shot. If you're not so luck, you're probably looking at a whole new EATC unit. I'm not sure if the 1996 has a separate motor controller or if it's like my 1993 SHO was, which was all integrated in to the $280 control head.
-Rod