It started about a fortnight ago, started the car it came on and it stops on, it seems that the second R flashes for about 5 minuets and then becomes constant. I've done a search and people have ideas how to fiddle it to pass the MOT, but not many ways to repair it, My car is 18 years old and I know they say the airbags need replacing after 10 years but there's a lot of Disco's out there over 10 years old without the SRS lights on. is there a fuse for the SRS, mine is a 95 reg and has no belt tensioners there. my horn works so the wireing in the steering column might be ok, any info will be handy thanks
Tony

Srs air bags are not monitored, the 10 year stuff is a recommendation, but the electrical circuit is.
Unless theres been some work under the dash to disturb the srs wiring connection the only other thing to look at is the flexable 'rotary coupler' that's below the steering wheel that is know to go faulty, not surprising after 18 years of use.
Yes there is a fuse like all electrical circuits and repair of the coupler is by replacement only, they can be found on e.bay.

mine came on after i left the ignition on, the gradual drop in battery voltage causes the srs black box to show a fault, eg low voltage, it has to be reset to make the light behave normally, although i did not bother. Im not sure if only landrover dealers can do the reset.

Disconnecting the battery does not cuase the fault it has to be a gradual drop in voltage.

Most SRS systems have 2 lamps in the dash, if one fails the other will stay on. Low battery volts as others have said will also log a fault which can only be cleared with diagnostics. diagnostics would be better than guessing.