The battery in my 2000 xj8 has gone south for the winter, consequently I can't open the boot. Can't start the engine, can't unlock or lock the doors using the key-fob, etc. How do I open the boot with no power? Any help would be appreciated. Thanks.

 

There's a keylock on the boot on my XJR, I assume the XJ8 has one too.

 

Yes, I have the same thing in the same place, but it does not respond. I assume there is also a switch inside it similar to the door lock. Thanks for the suggestion.

 

As long as you use your valet key it should open trunk? Push down on trunk lid wiggle key...plastic scraping will open door locks ez

 

https://m.youtube.com/watch?v=zwz1N8NUy-4 How to unlock

 

The green valet key does not open the glovebox and trunk. If you have a black key that doesn’t open the trunk, you need to use some WD40 in the trunk lock hole and try several times inserting the key and spraying WD40.

 

As far as I'm aware its a completely mechanical lock. Can't imagine putting the battery in trunk and not having a way to get to it if its dead. Squirt some lubricant in there and work your key back and forth without forcing it...its probably just mildly seized from lack of use.

 

You can energise the car from the engine compartment via the bulkhead positive stud:

 

To open, turn the key clockwise. The first 45 deg. has little or no resistance then a fair bit of resistance up to 90 deg. when the unlocking takes place. The unlock is easier if the boot lid is pressed down in the centre while turning the key 45 to 90 degrees.

 

As addicted to boost has suggested needs to be done while you charge your battery from under the bonnet.
All locks are a maintenance service item often overlooked due to the convenience of fobs.
Do you have 2 key's and are the tips the same.
Are you able to lock and unlock the driver door with both keys. Unsure if car was unlocked.
I have seen ignition locks changed but not the door or trunk to match when the ignition barrel wears.
It is easy to rematch all your locks if different.

 

Another method is to connect 12 volts, then turn the key in the door lock and hold.
The windows will all retract, and you can then reach in and hit the trunk button. Of
course this method is entirely frivolous if you have a working key fob.