With the rev counter there's a brown lead going to the alternator. It was happening to mine , Maybe it needs to be pussed back on or wire stripped back & new connector put on.
Check all your pulleys are tight before fitting a new belt , Mine has shredded a few belts over the years and it's usually because a pulley is loose or worn.
There is a black relay under the steering wheel ,Maybe it's knackered.If you don't mind not having indicators just pull it out. I've changed mine a few times over the years.
Here you go ,Very quick delivery.:)
https://www.ebay.co.uk/ulk/itm/271839899718
Land Rover Discovery 1 LED Green ALL Dash Dial Instrument Bulbs 200tdi/300tdi/V8
Just noticed my 300 tdi 95 disco dashboard lights on my needles don't work. Everything else lights up. A bit of a pain driving in the dark and can't see the needles,Any ideas. Cheers
What year is your disco ? Mine is an earlier one with the seat belt clip booted to the floor. Later ones are to the seat.
Some RRC seats will fit ,Little bit tight with the front arm rests touching the cubby box.