A strange electrical fault has developed on my late 09 RRS. Something is draining around 5 amps off the battery when everything is switched off, suspension lowered and locked up.

The battery is good - charges up and holds it's charge overnight.

No drain through the starter motor or alternator wiring.

After pulling all 80-odd fuses and most of the relays that are accessible, the only change is when FL15 & 16 in the engine bay fusebox are both removed, the drain falls to 1.5A. Unfortunately, this kills everything! The owners manual doesn't tell us what these 40A fuses do, so I'm stumped.

To look at the problem another way, a short somewhere would blow a fuse so it would seem that there's some component drawing 60W of power that's not shutting down when the ignition's off.

It's booked into the main dealers tomorrow, Any ideas before I'm presented with an enormous bill?

FL15 and FL16 are fusible links rather than fuses and they appear to be permanent lives. They supply to lots of things including lights, locks, ECU etc. Not sure they're much help, as you've found out.

Have you checked the tail gate upper switch - the one that opens the glass hatch part? That corrodes and has been known to cause battery drains. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

Might not be at all relevant to you, but when my battery was going flat and drawing far to much current when all off, it ended up being the drivers door not double locking properly, but then started to try every few seconds, no alarms etc sounded, so not aware it wasn't locking. Once sorted all returned to normal. A strange fault from something you wouldn't be looking for.
LR dealership spent two days with no joy finding fault, my brother though had recognised this through a RR they had doing similar, and it was that.  John

RRS MY12 SDV6 HSE. Sumatra Black/Ebony & Walnut + Dynamic Pack, + Cold Climate Pack + Memory Pack, Digital TV/DVD, Premium Leather, Cornering Lights, Cooler/Fridge Box, & most Options.

I was was think they maybe for the lights but forgot to check the diagrams.

Thanks for the replies, but apparently it's the fault of the alternator after all.

It's only putting out 12+V and the fault is preventing the management system to go into switch off/sleep mode - hence the 5A drain on the battery.
'
New alternator will be fitted on Tuesday, I'll keep you posted. (Hopefully this will then be moved to 'faults and fixes' thread!)