I took apart my D type BFM to see about getting the security light to work. Although the circuit actually exists on the circuit board, none of the components are present.
I populated these components and tested the board:
The other problem is that the gauge silkscreen doesn't expose the security LED, so I carefully cut out the underlying shape (which was a key)
I put in translucent red acrylic behind that hole and once installed behind the smoked plastic lens of the BFM, it disappears.
Here it is all complete
Seems to work just fine.