1998 Chevy Cavalier - ABS Light stays on

Hello! At first, the ABS light would come on intermittenly, and if you turned off the ignition, then back on, it would stay out. Now, approx. 2 months later, it stays on all the time. Ichanged the ABS relay in the fusebox under-hood, but that wasn't it. Checked ALL fuses related to the ABS system, no luck. I passed inspection (NJ), but conditionally, with an "advisory" to have the problem remedied within 60 days, or face sanctions. I have a feeling I won't be able to find an honest enough mechanic to check the system, and have them say it's going to be a several hundred dollar job. Anybody, any thoughts?

Thanks so much!
Warren