P00BROWN

Hi all, I have an 1990 xj. I followed all the threads on the up grade on the booster and mc. The thing is that I did not change out is the prop valve from abs to non abs. Will this cause my brake light not to work? From the old system when the brakes are not working the dash brake light would come on and the brake lights would not work. It's doing the same thing after I did the change over. Was I suppose to change the prop valve from abs to non abs? Did I missed a thread to delete this Bendix? I am stuck. Thank you