Walthers 90' Turntable...

[eightyeightfan1]

I have the 90' manual table. When I assembled it, I sodered two Code 83 rails together. Instead of using the wipers(which may explain the intermitten running), I ran two wires(soldered to the connectors) right to track power. There is also a thick black washer that goes under the bridge, that I haven't installed yet, but I do get derailments on the bridge, and I think that is why. the loco steps up on the bridge and the weight tilts the bridge to that side, causing it to move enough, that sometimes, the rear wheel set derails.

Pic of the soldered joints, which look like they need a cleaning.
   

View of the wires.