[Elliott]

My 550I had the battery replaced and the trunk won't open. The switches won't work and there's no way inside the trunk from the back seat. Any suggestions?
thanks

[95blkmax]

pop the hood and use the jump posts on the passenger side strut tower to provide 12v power from another car (or a jumper). Then you'll be able to open the trunk

[Qsilver7]

And regarding the battery…I wonder if someone did not put something back correctly…or didn’t tighten the battery terminals enough…or didn’t put the battery tie down clamps back properly which allowed the battery to move….which can also loosen the battery terminals.

The positive side has multiple connections (like up to 5 depending on setup).

When you get the trunk open…post back what you found.

[StradaRedlands]

Originally Posted by 95blkmax

pop the hood and use the jump posts on the passenger side strut tower to provide 12v power from another car (or a jumper). Then you'll be able to open the trunk

This would work with a dead battery, but if the negative (most likely) cable isn't attached properly at the battery, it may not. I've read horror stories of similar situations, but no personal experience.

[Qsilver7]

It should still work (engine bay terminals) even if the negative battery post is NOT attached or even if the positive terminal is not attached to the battery. If they attach to the dedicated negative post in the engine bay (instead of selecting a bolt on the strut tower or other metal piece that they think is grounded…which may not)….then the vehicle is still grounded if 12v is running though the engine bay terminals.

What could stop the show on the f10 is if the 12 volt connection that runs to the electronic boxes is some how disconnected. You can see in the pic in my post above that there are approx 5-6 connections on the 12 volt side. I’m not sure which ones carry power to the e-boxes…but like in the pic below…as long as the BST is intact, power continues to the fuses even when the positive terminal is removed from the battery.

You can see an example in this simpler setup found in the e53 x5 positive battery cable run from the engine bay to the battery onto the electronics box. Again, if power is applied to the terminals in the engine bay…as long as the battery safety terminal is intact…12 volts will continue on to the electronics…because the negative terminal in the engine bay will provide the ground.