Here you are,
https://www.halfords.com/motoring/battery-maintenance/battery-chargers/ctek-multi-mxs-7.0-battery-charger-280326.html?cm_mmc=Google+PLA-_-Motoring>Motoring+Products>Battery+Maintenance>Battery+Chargers-_-Motoring>Motoring+Products>Battery+Maintenance>Battery+Chargers-_-280326&istCompanyId=b8708c57-7a02-4cf6-b2c0-dc36b54a327e&istFeedId=62b447cf-331e-4fec-a47a-9985ff72d404&istItemId=xxwptr&istBid=t&_$ja=tsid:|cid:17363835999|agid:|tid:|crid:|nw:x|rnd:8901391371687815951|dvc:t|adp:|mt:|loc:1007258&gclid=EAIaIQobChMI2pi56uO9_AIVnIBQBh3EugjwEAQYASABEgKgsvD_BwE
Check the voltage of the new battery first as well as the connections.
Change the batteries in the remotes.
Check the brake pedal switch is working correctly.
Try again.
You may find the parts here or failing that, I believe you can download the parts catalogue from SNG Barrat.
https://parts.jaguarlandroverclassic.com/c2n3418-sill-closing-panel.html?gclid=EAIaIQobChMI5P_S-K-9_AIVh9DtCh2vfwavEAQYBCABEgJCiPD_BwE
The problem is, over time the tangs become brittle so even taking the wheel off can lead to breaking them. You could try warming them up slightly to make them more pliable.
Sorry to hear that Martin. This may be of help should you need it.
https://www.ebay.co.uk/itm/JAGUAR-XK-SPORTS-X150-2006-2008-4-2-AJ-V8-32V-ENGINE/202715961061?hash=item2f32d016e5:g:gtAAAOSwfrJZx-cT&redirect=mobile
Welcome to the forum.
Your thinking is probably correct and a code reader would confirm. Door locks are a common problem and should be replaced though do make sure you get the right type.
The control box or module is what the sensors plug into. You will find it in the boot, probably in the spare wheel well. When you locate it, disconnect the connectors and check for corrosion as well as signs of moisture.
Not unheard of but thankfully, a rare occurrence. The fact you shut the car down immediately stands you in good stead.
Hopefully not too expensive to put right.
Haha, good point I forgot about the speed, though mine work at low speed whilst turning into streets. A dark lane would be best as you can definitely see when the light up.
Turning the steering wheel activates them. To check, have the engine running and lights on then turn the wheel left and right and have someone look to see the light activate.