Hopefully my last question about UCS tracks & controllers

Pushing the uncouple button puts voltage on the magnet coil and both of the control rails. Thus you have both types of couplers working but not the unload system. That needs both voltage on one control rail and ground on the other.

41woodie posted:

... When I push "unload" the solenoid on the operating car works properly but the coupler on the right end that shares the wiring with the coil also opens.  I wouldn't think that would be desired result of "unloading" but from looking at the schematic it appears to be correct.  Any thoughts that would unconfuse me?

Well, you have it all working properly, and you have discovered the disadvantage of the 3459 & 3451 cars  vs the later 3469 & 3461 updated cars(with magnetic instead of coil couplers) ...is that on the earlier cars, one of the couplers will come uncoupled when the unloading mechanism is activated.  This wasn't an issue when this system was developed in the prewar era(1938) because the box couplers work by gravity and the train remained coupled when you released the "unload" button.   Not so with the knuckle couplers used in 1945 & after.

The transition to magnetic couplers started in 1948 with many items changing catalog numbers slightly to reflect the difference.  Several items like passenger cars continued with coil couplers beyond 1950 until magnetic/electro-mechanical replacements were engineered or the item was discontinued or redesigned with different trucks.

Rob thanks for the explanation of the workings of UCS tracks.  I was pretty sure that I had everything wired correctly but then I screwed up by applying logic to the situation, Lol.  I've only been at this for about a year and I'm still surprised when I run across something like this from Lionel.