Robert,
Your other problem is an insufficient ground problem due to the isolated wheel sets and excessive black coating on the wheels.
I removed the nylon bushing in the pilot truck and replaced it with an aluminum one.
I soldered jumpers from the axle to the back side of the tender wheel set that does not have the wipers. While the wheels were out, I removed the black coating. I also removed the black coating from the two un-tired drive wheels.
Most don't follow the ground issue advice but trust me, IT WORKS!
Hope this helps,
Dave