I recently acquired a 1947 Lionel “R” Type 110 watt transformer. While checking it out, I found all terminals function correctly, except the variable A – C terminals. All the internal wires are connected and I can find no broken or disconnected wires. I have cleaned the contact area on the coil and the contact arms. The contact arms are making good contact with the contact area on the coil. The other 3 variable (A – F, B – C, B –F) terminals are working correctly.
Does anyone have any ideas why the variable terminals (A – C) are not working?