Okay So I must ask BRRRRR stupid but.........Can sombody tell me where I can find main relay in a 2006 Z4 E85 N52 6 speed manuel trans. It is not in the ECU box, and I can not find it in the engine bay. 
MAIN RELAY??????
- Thread starter Roger Holdorf
- Start date
Attleborough, Norfolk
What is the problem first of all.Roger Holdorf said:Okay So I must ask BRRRRR stupid but.........Can sombody tell me where I can find main relay in a 2006 Z4 E85 N52 6 speed manuel trans. It is not in the ECU box, and I can not find it in the engine bay.
There is a main fuse.
My battery drains over night
And what are you trying to achieve?Roger Holdorf said:
If you want to stop the battery going flat then just disconnect it. But you’ll need to find the source of the drain.
First thing to check is to make sure all the courtesy lights turn off including the one in the centre arm rest.
Yes most are tried. All fuses inside and outside, doors, hatch, hood IBS sensor light switch, not very much left exept from relay.
No I can`t find any, but I have seen som pictures where there are some relay in the ECM box. And I was thinking that if the relay was faulty and give power to the ECM at all time then I new the reason for draining the battery. It is strange I have changed the ignition switch and the main light switch with now success. When I dissconnect batteri I measssure about 11V between batteri minus and the car. The diagnos says the the car does not dobbel lock the doors so my next possebility the immobilitzer or also a component called GM5, HAPPY NEW YEAR! 
Pull the fuses one by one and check which one stops the current drain.