On Tuesday, 22 October 2019 13:22:55 UTC+1, wrote:
BMW 7 Series 3 years old. Has tw lights in the boot. One under the parcel shelf and one in the lid. No sign of water ingress. Very strange. Any bright ideas out there (excuse the pun)

If it's blowing a fuse there's a short somewhere. No mystery about that. You just gotta find it. And that's no fun. I'd start by removing the lamps so there's zero load, then replacing the fuse with a resistor, and monitoring the voltage on its output. Disconnecting bits where accessible will show you when the short goes away.


NT