Weird one here. I have a 2003 R53. Parked it the other day and then came back out and the car was totally dead (no power, no dome lights etc). The car has a new battery. When I checked the voltage at the battery, I got 12.4V. When I checked it at the + terminal in the engine compartment I got 3.4V. The main fuse in the trunk shows continuity.

Any known issues or ideas why I would all of a sudden see a 9v loss between the battery and the positive jump terminal in the engine bay? Any connections in the main power wire? I assume one main hot wire goes to terminal and then the starter and the second goes through the main fuse to the fuse box.

Anyone have a schematic they can share or a link to one?

Thanks!
Chuck

 

Found it. Corroded connection on one end of the main fuse. All good now. Course I noticed one of the motor mounts need replacing. Has anyone started to go full circle? I'm now fixing things that I already replaced one. AC clutch coil, low speed radiator resistor, oil filter housing....

 

good to hear you found it. how long have you owned this car?

 

5 years

 

Do you have a picture of that?

Several years ago, when I went to replace my battery, I found the battery sitting in about 4" of water back there. That orange, high amperage fuse box was also submerged and found to be rusted. I cleared the drain hole in the battery box and then fixed the leak (boot handle/license plate lighting gasket) but that fuse box is still all rusted up. I've been meaning to replace it, but you know...

I'm just curious how yours looks compared to mine.

 

Yep, that's it. The fuse is in the orange box. My hatch was cracked and it trained and filled my battery box with water. That's what corroded the bottom connection to the fuse.

 

Thanks for the clarification as to where the main fuse is located.
I didn't have my Bentley at hand and was searching for the fuse thinking it was in the engine bay...

No problems here. Just wondering where the main fuse was.

 

makes sense. 5 years some maintannce items start to come back around. re the motor mounts. the stock ones dont seem to last very long

 

"... 5 year maintenance items ..." I keep looking at parts I swear I just replaced and as it turns out "just replaced" was 12 years ago. Oh, the joy of having older vehicles.

Motor On!