ABS Inop

yesterday my father and i were driving on the highway and we noticed that the ABS INOP light came on, he has a 1993 camaro rs, what would be the possibilities that would make this light come on?, also whenever he turns on his lights for night, the turn signal lights come on but don't flash, they just stay lit on the dashboard, what would cause that?

ABS inop, probably a bum wheel sensor. You'll have to check for codes.

As for the lights, I'm not much of a 4th gen guy, but they did have some problems with the rear tail light the first few years. Or a bad flasher?