GG1 Binds & Sparks on 072 Fastrack Switch

Hi Bruce I doubt if this is causing your problem, but I had a Williams engine that would not take even an O72 turn. It turned out to be that the factory ran the power wire to the motor wrong and it hung up on even the slightest movement of the power truck left or right. In othe words, the darn power truck would not swing even a quarter of an inch from center.

I could be behind the information curve here but Fast Track switches have a good reputation for being smooth operators.

Bruce; Go with Mario's suggestion; it's likely a mis-routed or too tightly crimped wire in a harness is restricting free-truck swivel motion. Take the body off the chassis and check for free movement of the offending drive truck assembly. 

You could check the wires that attach to the problem truck for the ground and roller hot.  It is possible ther are shorting against your frame and giving you binding.

Also, the ground and center rail wires could be in close proximity, which rubs through the insulation. I would recommend, as have others, that you take the shell off the loco and run it through the turnouts, that will be self demonstrating, especially if you dim the lights in the room.

Thanks for all your suggestions. I did take the shell off the body, and did't notice any wires binding. I will try running through the switches with the shell off, although I will have to disconnect the wire running to the catenarys.

-bruce

On the truck that binds, is it possible that there is a wire pinched between the motor and the truck? (Voice of sad experience). That would inhibit the truck from moving as needed, and wear through the insulation causing fireworks.

Check that the collar holding the truck isn't the culprit. The sparking sounds like it's from the engine dragging a binding truck thru the switch not a wire problem.
Get out your phillips head and check every screw look for burrs
Make sure the roller assembly is tight and lube everything
Good Luck
David

Thanks David. I took the shell off and double checked the wiring harness, and there are no problems there. Ran the chassis without the shell with the lights off, and the spark only comes from the bound truck dragging through the switch, not from any wiring above.

Both roller assemblies appear tight and spring well, and are recently lubricated. I will check the bound truck for burrs.

Thanks everyone again for their suggestions.

-bruce