If, when you press the brake pedal or select reverse, your disco II illuminates the diff lock light and goes "bing bing bing", this means that it's blown fuse #25, which appears to supply both brake and reversing lights.
In other news, it's taken to going down on the left-hand side when parked for more than an hour or so. I suspect an air leak. Goes up again fine when started (provided all the doors are shut properly).
There's no audible leak, although it takes long enough to go down that it wouldn't really be aduible. Is there any known leak-point, or is it a variable thing?
I left it in high mode when I parked it this evening, will see if it still goes down from there. I'll also pressure-wash it tomorrow and then see if I can trace any leaks with soapy water or something. The height sesnor on that side seems to work, it's connected and not siezed, anyway.
'course, it could be a leaky airbag.