There is a half moon seal at the rear of the rocker cover gasket on a TD5, it is often the source of leaks at the back of the engine if it has not seated correctly.

They could fit scotch lock connectors in the electrics to build in unreliability to make it authentic.

The bonnet alarm switch is the most likely suspect, my defender and my next doors range rover have had this, ensure the alarm switch on bulkhead is straight and being pushed down when bonnet is closed, the rubber cover on the switch maybe split, mine was and I fixed it with super glue,

Letl us know the outcome, it's always good to get feedback. Hope it is something as simple as they suspect and not cost an arm and a leg.

Ran out of diesel. Fuel pump or filter choked, Battery low and not turning engine fast enough. Disconnect fuel line to fuel pressure regulator and see if you are getting diesel when cranking.

Have a good look at your swivel balls if they are pitted replace them with the newer teflon coated swivels as mentioned above that is what causes the seals to be damaged and leak. I had to replace mine due to pitting and "grease" leaking down the back of the wheels.

I fitted a new super heavy duty truck battery in my TD5, before removing the battery I connected my C-Teck battery charger (set to supply mode) to the under seat fuse box to live connection where live cable comes in from battery and negative to a convenient earth bolt, I then slackened off the...

Sounds like relay problem.

Yes TD5 does have a fuel cooler on fuel return flow.

The ECU will default to a setting that will be ok to drive.

Poor/loose fob battery connection maybe.

https://www.sp-4x4.com/ASR1154_defender_RH_bulkhead_vent_flap_p/asr1154.htm https://www.ebay.co.uk/itm/165754301660

Try slackening the hinge bolts on the bonnet and lining it up the re-tighten the bolts.

You should be ok, I have found this in the MOT manual. Says from 2018 and when engine turned off not lights. But side lights and your DLR lights will stay on when engine turned off if left on. You only need to inspect daytime running lamps (DRLs) if they’re fitted as original equipment to...

I "think" daylight running lights have to turn off or dim when headlights are turned on to be MOT compliant, therefor a relay would be required to drop out the power to the running lights when headlights are turned on.

Or use zip tie. Some rubber gaiters come with zip tie retainers.

Relay 4 under fuse box, 4th from left.

My TD5 does a brake panel light check, I have just tried it with the hand brake off and turning ignition on the light comes on for a couple of seconds the goes off, with hand brake on it stays on until brake lever released. A different vehicle I know but it may work the same way.

My understanding of the fuel system is the pump runs continuously and fuel pressure is controlled by the fuel. Pressure regulator and excess fuel spills back to the tank after going through the fuel cooler.