Battery in trunk - +12 volt battery source in engine bay as well?
 

is there a positive 12 volt battery source under the hood in the engine bay in a 400e with the battery in the trunk?

I've been trying to figure this out as well. The BMWs have a terminals in the front.

anybody have any ideas? Is it the thing behind the CAN?

I don't know specifically about your car, but I seem to remember that on some cars with remote battery there is a Red Positive (+) terminal under the hood that connected directly to the battery.

No Black Negative (-) terminal, they expect that you'll know that you can use the frame or other grounded metal for Negative... ;)

Have another look for a Red plastic cap, pop it off and see if that's your Pos terminal.

Best Regards,
Jim

On our '98 E320, the battery is under the back seat. However, there is a connection that can be used for boosting etc under the hood on the driver' side - I think that it has a red cover that hinges up to expose the lug.

It is not so easy to find a ground connection because the engine has a complete plastic cover - The manual says to connect to an engine lifting lug near that back of the engine.

Read your manual under boosting - it should show these connections.

found it. Its under a black plastic cover behind the CAN box on the passenger side. Thanks

90free400e,
Can you post a picture exactly where it is? I cannot find it. Is it really behind the CAN box? How can you fit anything behind there such, as jumpers?

ill try and get a picture. But its sort of a square plastic cover that will pull off. It has about 6 cables attached to vairus connections along a metal plate running to various parts of the motor.