Tap on the pads likely while watching needle. You should have nearly no movement with dial on cylinder and tapping on either shoe pad. Same goes for dial set to shoe and tapping on cylinder. I say this for we had alot of machines back then that had two wires turned around in harness. I know you say it worked different last year but you should check this out. There was a bulliton on this in about 1992 and I seem to remember the bulliton is wrong as compaired to how it actually works. Check it out