That was the problem with the GS-4s. I have run into several second run units that were of the same design as the first run units.
I was told that some how some of the first run frames got mixed with the second run units. The first run frames were supposed to be destroyed when the second run was made. I was told that about 7% of the second run units had first run frames. I think I have seen everyone of them. LOL.
I don't take and chances anymore- I just isolate the motor 100% and wire the motor with wires to the decoder. The draw bar motor contacts are no longer connected to the motor nor the decoder.
