I do have to agree with Kev it sounds like it’s been wired straight to earth. Check the switch terminals and operation with a multi meter

Is it an illuminated switch? can you post a link to the switch?

Unplug the interior sensor and try the alarm. If the alarm goes off plug the sensor back in Open the bonnet and tape down the bonnet sensor. Try the alarm again if it still goes off, take in to Land Rover garage plug it in and ask them to tell you what the last 10 alarm activations were.

if you hook it up to Computer it saves what sensor triggers the last 10 alarm activations. or unplug Each sensor one at a time over night until the alarm stops going off, plugging it back in when you wake up.

Dont rule the battery out yet I’ve had two within the last 3 years that have failed one of them with in a week. with the engine running what’s the voltage going into it?

The dvla used to do a service where they would contact the owner of the a car and pass on your details if you previously owned the car.

Have you put bigger wheels and tyres on by chance

There was boat yard near us, they used to use a Heinz branded tomato sauce pump descender to put oil in the bottom end of of out board shafts. something like this.

2 minutes 50 seconds.

I know you have said you have checked the earth but if you can just plug the positive going to the led light and take the negative straight to ground. if that doesn’t work you now it’s something with the feed not the earth side. also confirm it the other way plug the negative in and take the...

I’ve see a few with just a plywood Sheet across the wheel arches all fancy carpeted and rubber matted and really useful or wolf boxes underneath. it really did look good to fasten the sheet to the floor They just installed tie down points on the floor and used a couple of d links and a few...

1” square garden trellis Netting 8mm shock cord

Always looking, only about 30 now off a full set.

They told me it helps clear the engine and exhaust out, if you cars going to fail on emissions take the air filter out so there is no restrictions and give it a good blast to the test centre.

I’ve seen a few cars with the air filter removed when it goes for the mot.

I’m a smidge taller than you, seat all the way back then tilted back a bit and just excepted the fact it I looked right I could see nothing but door piller and had to put my head forward and then look.

If your aerial isn’t dab compliant your never going to get any digital stations. You may need to fit a digital Ariel to your windscreen.

There is a way in the software to find out what caused the last ten alarms to go off. The garage showed me it, for me it was the sensor plugged in a new one and it was fine. £35 I think it was.

https://www.landyzone.co.uk/land-rover/happy-with-my-defender-tdci-double-din-conversion.318622/