Martin,
I would turn off the Logix for now while we figure out what is happening.
Now for each block is there a single feed wire going through the BD20 that
then goes to the block. All the current for that block must feed through the
BD20. Your symptom sounds as if there were other feed wires to the block so
only some of the current is passing through the BD20. The test for this is
disconnect the feed wire through the BD20 and see that the track block is
now dead. If not, current is getting there somehow.
-Ken Cameron, Member JMRI Dev Team
www.jmri.org
www.fingerlakeslivesteamers.org
www.cnymod.com
www.syracusemodelrr.org
Ken Cameron