TonyWalsham said:
Ed.
I think you will find it is actually the other way around.
The early models had three wires.
The later models had four wires to accomodate DCC capabilities.
Well here is what Silvergate had to say. I am no expert so I followed their directions:
"I am pretty sure that yellow goes to the outside contact (pin 4).
I will probably be yellow - white - brown - green .
The old-style Uintah gearbox has the motor wires (yellow & green) running next to each other. The Sumpter Valleys, (in the traditional LGB way), were ordered yellow - white - brown - green. "
I am the original owner of mine. I bought it when they first came out so I know it is an “old style” Unitah gearbox and it has four wires.