L405 ATB '14 4.4sdv8 I've got no power to many modules currently, think is earthing maybe but need to get into boot (want to check both batteries directly) however no power to lock system. Any way to manually release tailgate? I've popped the panel off rear lid but the actuator seems to not want to pop the lock without power??

Not sure on the tailgate, but you should be able to use the ski hatch behind the rear arm rest to get access to the boot area if that helps.....

thanks yes I can get into the boot itself (via internal middle section as you say, thank you) and have popped the panel as mentioned to try the cable but can't get it to pop the boot lock.

I can't get the floor cover out to get to the battery as theres not enough space to remove it without opening boot or moving seats. I have no power to rear seats so cant move them.

I'm charging battery, and starting to think it needs replacing, probably aux as well. And am gonna check earthing points shortly, but thought if I could remove battery and check separately to car then this would be a start. Also I guess I can buy a battery checker and attach to poles under bonnet.

Nothing in the owners manual that I can see.

It does seem a bit bonkers that you need power to get to the batteries.

As you said, all you do is try to charge, or jump another battery onto the under bonnet connection points.

Hooked up a proper car 🤣 to the RR - my 335d - and the volts are coming up to closer to 15 and this has let me close the rear window which was open and not closing with lower volts. So this is saying to me the battery(s) are fubar so I would replace these if I could get to them 🤣🤣

(My worry with warranty now is if I get it collected they will hit me with “consumables” bill if it is a battery)

However still nothing from dash only “hold key near thingy”
The infotainment switches on ok but nothing that runs the car.

Next step is just check the earth points

I connected a Booster (PowerBank Starter). I had the highest Booster on the market with a peak current of 25000 mAh. But I couldn't start the diesel, but I was able to energize the on-board network and open the trunk.

Good plan.
I ended up taking rear seats out and replacing both batteries - they were both 9yrs old so had done their time! not sure why not replaced before then. Anyway, it's been good as gold since then.

Nothing like a bit of pre-emptive maintenance with these cars in particular, -don’t wait until something fails in possibly unfavourable circumstances, particularly with consumables. “If it ain’t broke, don’t fix it” -where’s the fun in that?

urman wrote:

I connected a Booster (PowerBank Starter). I had the highest Booster on the market with a peak current of 25000 mAh. But I couldn't start the diesel, but I was able to energize the on-board network and open the trunk.