where dose the hand brake light attached to? the brakes or a switch by the handbrake like on subarus? hand brake light should be a easy fix the abs light can you plug a obd tool into cant remember the age? could you damaged the cable brake lines refitting the diff the ratio of the diff i dont think would effect the abs damage to wiring / sensor would and take it you have bleed the system ?
The hand brake light illuminates if there is a brake problem, so ABS light on, the handbrake light light will come on to keep it company, there is only one ABS sensor on the rear, this is on the top of the diff housing, driven from a ring on the crown ring, bleeding the system was done to remove the air from when the single brake line was disconnected, would make no difference to my current problem.
I will plug into it, but info on these is very limited.