The brake system has more or less been replaced, except for the master cylinder and the ABS light will not go off. It went out for about a minute when we were finishing up bleeding the brakes but came back on and stayed on when we backed it out of the gargage.
What year S-10? And how were the brakes bled?
I doubt the ABS problem is with the braking system. Did you mess with any of the wheel sensors? Sometimes, brake dust can build-up on the sensor, and make it hard to see the encoder wheel. This will set a code and turn on the light.
from farthest from the master cylinder to closest. Pump the break pedal method
When you compressed the piston back into the calipers did you open the bleeder? If not that could have set the light.
A 1994 S-10 with ABS brakes??? Few CARS had ABS brakes in 1994… Is this a 4-wheel ABS system or the version that just prevents rear-wheel lock-up?