Any help would be very helpful.

I was jump starting another car from my Range rover (4.4 v8 vogue). When using the positive jump start point in front of the battery on my range rover, the positive lead accidently touched the bodywork causing a small spark. I thought nothing of it. After jump starting the car I drove the range rover back on the drive as normal and turned it off. Ten mins later when I had to go out, I got in and it would not start. The clock went all the way around to 12 o clock, then after this all electrics failed, no lights, it wont even lock on the key fob. Nothing whatsoever.

Any Ideas, please.

I have disconnected the battery and I will re connect in the morning. Gone:

Golf GT TDI 150- Still got.
BMW 325TD
Range Rover Classic
Defender 90

Lets hope the reconnection works

Sounds bad, RR have so much in the way of sensitive electronic components that a direct short could do all sorts of damage. I would start by checking fuses then try & jump start it (without shorting anything) & check you have a charge as you may have blown a diode in the Alternator, which could be seen as the lucky option. But you can check you are getting 14.5 v aprox at the battery & if so time to start testing components/wiring.
Mike Worse things happen at sea! Well thats what swmbo said when WRENS came to sea!!!

Hi Oliver and measure the voltage of your cranking battery and do this at the battery’s terminals.

Then measure the voltage at the Positive Jump-start Point.

If the voltage at the battery terminals is down round 7v then there is a good chance you have done some harm to your alternator.

If the voltage at the battery’s terminals is around 12v but you have no or a very low voltage at the Positive Jump-start Point, then you have probably blown the pyro in the positive battery terminal clamp.

It is highly unlikely that any of your electronics were damaged. 2007 TDV8 Lux

My guess is you have blown the 5amp BCU fuse in the main fusebox (under the CD multiplayer)

Lesson to learn here............... ................. Don't jumpstart cars with a RR IMHO it's not worth the risk

Thank you for all of the replies. I now have some idea what to check for and do. I will let you know the outcome. Thanks Gone:

Golf GT TDI 150- Still got.
BMW 325TD
Range Rover Classic
Defender 90

when this happened to my FFRR several years ago, it blew modules attached to the steering column. Downside was that they were not replaceable, came with a whole new steering column, and not cheap  RR Sport Supercharged Vesuvius Orange 4.2 V8 First edition

Thank you for all your help.

Just to let you all know, I disconnected the battery over night. This morning I touched the terminals together then I re connected both of them.

Luck must have been on my side as she started first time, did the steering from lock to lock, and now everything seems to be fine. Gone:

Golf GT TDI 150- Still got.
BMW 325TD
Range Rover Classic
Defender 90

You lucky lucky b d........ Now go buy a lottery ticket as the last one like this cost over £4k at the dealers to put right

Nice one. See our cars are not all bad.........

Had similar luck lately.

I was driving through the city on a small one-way street when a guy holding jumper cables flagged me down. The street had cars parked on both sides but it was so small that by stopping I was blocking traffic completely. He told me that he'd been trying to get a jump for some time and was very late for something or other. I really try to be helpful (and hope for the same when something happens to me or someone in my family) so, because of the traffic backing up behind me, I jumped out of the RR, popped the bonnet, and ran around the car to attach the leads while asking all the questions I would normally check for myself: is he sure it is the battery, are the leads attached correctly red-red black-black - is he really sure? Yes, yes, yes...
As I went to attach the neg lead - huge spark and my motor's idle dropped momentarily. Disgusted, I went over to his battery and sure enough, the terminals were reversed. In his defense I do have to say that, because it was an Opel (Vauxhall) and they put winter coats around the batteries (insulating covers), it was very hard to see - and to make matters worse, Opel had a red mark on the ground strap.
The best part was, tho, after correcting his terminals and trying again it was very clear that it was not his battery. I asked him to turn on his headlights - bright - and trying to start did not affect that brightness.

Lesson learned. I will still help people with a jump if necessary, but never rushed like that again.If the stranded vehicle is OK (no major shorts or a battery that is an acidic lump of lead oxide) and you follow proper procedure (bad batt connected first, then pos on the jumping vehicle, then neg) there is not that much that can go bad - even on a RR. But def something to be careful with. 
RRC 2Dr, RRC 4Dr,
P38, and 2 L322s
(wife thinks I'm nuts - prob right, too)

Glad it's all sorted
And good info about jumping from the FFRR or not should I say

Lucky

I'd just be too scared to try and jump with a L322 (or the new one). Just too many computers. Disco1 - sure. No problem!

Done it a coulple of times, no problems so far......

Oliver you are a lucky man!  There is nothing that can't be fixed with a hammer😜😜
FFRR 4.4 SDV8 Autobiography Santorini Black.
KIA E-Niro 4+
2021 Discovery 5 D300 MHEV commercial

The owners manual says it's fine to jump and be jumped started on the FF, I tried on mine when she had a flat battery but did not work as it was new battery needed!

very lucky though  If it dont work.......burn it!

If the IId tool cant fix it.......burn the FF.

If the FF cant be fixed......buy a Land Cruiser!

If the LC cant be fixed..............................................BUY a horse !!