Is there someway to tell if I have ABS on my '98 F150 with a 4.6L. I have the idiot light on the dash which comes on when I start the vehicle, but it doesn't drive like it has ABS.

 

A 98 likely has RABS (rear-only).

Look at the front wheel spindles. If it's 4WABS, there will be an electrical cable going to the sensor for each hub and the hub will have a toothed gear on the back of it. No cable and no teeth, it's RABS.