I have had a couple issues with my subway diverter and Pin Guy was good enough to assist the last time and help me (thanks Pin_Guy) I had a blown transistor on the aux driver board that had gone south. Replaced that, related fuse verified that the tieback was still in tact which it was and all was fine in STTNG land once again. If your diverter coils are not working, I would be willing to bet that one of those transistors that Pin_Guy referred to is toast. Easy to replace. Good luck.
G