I have 2 Bachmann #6 turnouts that short whenever an engine touches them when set to straight, engines pass over the frog just fine when diverging but the frog polarity shorts when in straight through position. The polarity of the track from all directions to the turnout is consistent. I don't run a lot of small engines so I never used the powered frog connection under the turnout. I have checked the gaps between the rails leading to the turnout and they are isolated. So there must be something in the frog/decoder that would change polarity when changing directions. I have 3 crossovers that work perfectly. Any ideas?
Contact the Bachmann service department - they should be able to help.