4 channel 12 bolt in a 3 channel car. I have ABS light on, AND Brake light. Normal?

I put a 4 channel 12 bolt in my 94 that was factory 3 channel... knowing full well that i wouldn't be able to use the ABS function. no biggie, i expected the ABS inop light to be on, but not the standard brake light? would this be normal. the sensor is not even plugged in, i left it on the old rear end. I put everything else back on the way it was. the lines are bled, the fluid is topped off. Just want to know if i should suspect something since both lights are on instead of just the ABS light

ttt