No battery in boot of xj6 how can i get it started

there is a battery pos post under the bonnet/hood but you should be able to open the boot/trunk using the manual key access in the boot /trunk plinth unless its siezed cos it has not been used try a bit of wd40 and work the key gently till it gets free

I think the battery is in the trunk or boot on this model ,i know mine is

Same car as mine with the battery in the boot ,disconnect the battery and use a 3/8th socket with a couple of extra extensions and a universal knuckle ,no problem shouldnt take more than half hour to get off .

Get another battery and make an adaptor cable with clamps for the battery plots at one end and a lighter jack (like the ones for phone car chargers) at the other. Now connect the cable accordingly (the minus plot on the battery to the side contact on the jack) and plug it in the lighter socket - now you will have enough power to open the trunk. Don't try to start the motor this way, it will fry the entire wiring harness.

its in the boot on my 94 one and then i just put the code back in the radio ,easy to do

Sounds like a total battery drain - something left on that you do not know of? Open the boot using manual over-ride (ignition key or cabin pull cord)

can you not open the bonnet?

when you battery goes dead, the security system locks the car. When you charge the bathery, use the key to lock the door and hold until the alarm activates. open your door and you can now start your [email protected]

Does it even try. (cough and sput) Will it start if you spray carb cleaner in it?

cover under bonnet with a big P on it and negative is anything metal on the engine