How are LED's in Doodlebug wired?

[BlueFox]

I took off the shell of my new Spectrum Doodlebug to add figures (coach, too) and replace the OEM decoder with a Tsunami 1000 for the Galloping Goose (I'm not sure what speaker to use yet) when I noticed that the passenger LED's didn't light but the headlight did.  After checking the OEM decoder plug I noticed 2 objects on the plug board that I was not able to determine what they were.  Anybody know what they are?  I'm sure they have something to do with the passenger area LED's lighting up as I can tell the normally unused plug pin #3 is connected to the unknown objects via circuit board trace and through-holes.

I find it strange that they dim when the headlight does but don't go out when in reverse.  Is there a wiring schematic somewhere I can see what they are doing before I continue?  This is no problem, I can work around it.  Just courious.

Frank