What brand of turnout is it?
Odds are you have loco wheels that are out of guage. Or if it is a Peco Insulfrog turnout, the wheel treads are bridging the narrow gap where the frog points come together - there are several solutions, usually employing paint or nail polish to extend the insulated part a little bit.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Just installed new Bachmann Dynamis DCC. Works great but every time loco goes over turnout the loco stops and controller shows short. Rebooting controller gets loco going again. Any ideas what my problem is ?