recently I replaced all the of the brake pads except the hand brake witch is pretty warn.
brake fluid level seems ok. I notice there are two cups with brake fluid, could the piping be slightly blocked?
has a load squeaking noise, when braking have any conection?
or is the light connected only to brake fluid level ?
The Brake warning lamp on Defenders is illuminated by TWO things. 1) level switch in master cylinder. 2) E Brake switch, located behind rubber boot of E Brake lever.
If you visually confirm that the level in the master cylinder is OK, I can pretty much bet your E Brake switch has stuck, from debris behind the boot, or the single wire has chaffed where it goes through the seatbox from the harness, below.