06 Defender 110 TD5 - intermittent start problem

Hi Guys,
First post for help here. I have been ripping around behind the dash sorting a wiper motor problem (fixed) and now have a start problem. IGN1 position shows lights but IGN2 does nothing - no fuel pump sound and no heater plug light. IGN 3 turns the starter motor but of course nothing happens. Another strange thing that I cant remember happening before is that the temp gauge goes straight to hot... I happen to have a spare new ignition switch because when I bought the car 3 months ago none of the doors locked... so I bought an entire set new from England anyway I wired it without taking the old one out - nothing changed. All fuses checked. The car worked fine after I put all the dash back, I left it a week and now its dead. Ideas? Or old thread? Cant seem to search old posts very well.

Have you checked the main fuses under the drivers seat base

Yep - just checked em again now...

May be worth checking the immobiliser , you should have a red engine light come up when you turn key to show immobiliser is on and won’t allow starting , have heard the odd story of these playing up time to time

Sorry - should have said Spurs - I think the immobiliser has been.... immobilised... the only red light on the console is not wired and the bulb appears burnt/melted.. I got the car as a sort of unfinished refurb project. Great body/chassis but shabby interior. bought it tried everything out drove it 2 hours home without a problem... usual story I'm afraid. I've still got my old Ford pickup for a couple more months - thought I would break the landy in gently.... glad I did now!

Problem solved - Spurs14 put me on the right track with the main fuses under the drivers seat. I worked back from there and according the Haynes manual (I know...) the 3 relays in the same enclosure are the main relay, fuel pump relay and the glow plug relay. Started pulling those - first 2 were ok but a little caked in scale on terminals... when I pulled the fuel pump relay it came off in my hand, holder and all. The main power cable was completely corroded for the first 1/2 inch - just blue powder. Re terminated cable, jammed the spade connector into the housing and off went the fuel pump and on came the glow plug light and engine light. Started first time. Pics attached (I Hope). Thanks for the help

Photos are not working, would be interesting to see them.

Great that you got it working.