I have a problem with a Lionel LW transformer that has me stymied. I recently took it apart to replace the whistle diode rectifier with a silicon diode. Upon reassembly, I now notice that when I push the WHISTLE button down, it gets to a point about halfway down where it cycles the E Unit and the train stops or reverses. Pushing it the rest of the way down restores power. This transformer does not lend itself to easily being able to operate and troubleshoot it when it is disassembled, as once you remove the chassis from its base, the whistle switch and directional switches come loose. I did check that the "H" shaped switch contact assembly is making contacts both in the up and down positions and cleaned those contacts. The issue occurs when that switch is in mid-travel. Perhaps if I better understood the route of current flow with the switch in both positions I'd be better able to understand what is going on. Referring to the attached schematic. The flow under normal operation is understood, since the rectifier and resistor are OUT of the circuit. Not so sure, though, what is happening in the PRESSED DOWN mode. It looks like terminal U is getting voltage via a normally closed connection of the direction switch, then, when WHISTLE button is pressed, gets connected to both ends of the diode rectifier / resistor wire assembly, that is in turn connected to the RED wire. I would suspect that when the button is in mid-travel, term U is temporarily losing connection with the GREEN wire BEFORE it makes connection with the rectifier-resistor wire. But visual observation of the switch action in an unpowered mode does not confirm that this is what is happening. Perhaps someone who has worked on this transformer before can make a suggestion. This is a spare transformer of mine that I can use to just power accessories, so no big deal, --it's just the challenge of getting it working right!
Gary L
