784 Hudson with Misbehaving E Unit

@cbq9911a posted:

-With the plug in the left jack (facing forward), the E unit cycles normally.

-With the plug in the right jack, the E unit is supposed to be locked in one direction.  On my engine, the E unit gets no power.  It won't cycle manually.

Please explain how you are attempting to get the E-Unit to "cycle manually" - what are you trying to accomplish?

Otherwise, everything else sounds right... plug left - F-N-R, plug right, no F-N-R. With the plug on the right, the loco will stay in the last state it was in before powering down and the E-unit should not get any power or it would continue to cycle.

Insert a toothpick in the side of the E unit and manually cycle the unit by pushing up the solenoid.

With the plug on the right, no power is passing through the E unit.  There's power going to the headlight, which is attached to the E unit.  There's no power going from 3rd rail roller to E unit to motor.

@cbq9911a posted:

Insert a toothpick in the side of the E unit and manually cycle the unit by pushing up the solenoid.

With the plug on the right, no power is passing through the E unit.  There's power going to the headlight, which is attached to the E unit.  There's no power going from 3rd rail roller to E unit to motor.

That’s how it’s supported to be….e unit not operating, ie; locked out

Pat

@ADCX Rob posted:

Please explain how you are attempting to get the E-Unit to "cycle manually" - what are you trying to accomplish?

@cbq9911a posted:

Insert a toothpick in the side of the E unit and manually cycle the unit by pushing up the solenoid.

OK, so you are cycling it manually, but the loco is not going anywhere.

If you pull the plug while it's running in forward what happens? The only thing that plug is supposed to do is disconnect power from the E-Unit coil... nothing else.

The E unit cycles and the engine stops.

@cbq9911a posted:

The E unit cycles and the engine stops.

Well, that banana plug completes the path from track power center roller to e-unit coil power. So if you’re getting a cycle when you unplug while it’s running, the only thing I can figure is when you’re unplugging it, it’s disconnecting momentarily when you start to unplug it, and it’s reconnecting on the way out, ….like it’s getting just enough of an arc on the way out to cause the coil to power up…..enough to cause a cycle,….Is the banana plug loose? Deformed? Wire on the verge of breaking? Something had to be causing a last moment cycle change as you’re pulling the banana plug out,….

Pat

@harmonyards posted:

...if you’re getting a cycle when you unplug while it’s running, the only thing I can figure is when you’re unplugging it, it’s disconnecting momentarily when you start to unplug it,..

Yeah, that doesn't make sense, unless there's some confusion in the terminology.

Repeat the test, but instead of unplugging from the jack while running, unplug the transformer from the wall while running in forward and then do the E-unit disconnect. It should remain in forward when powered back up.

Turns out the 784 was wired incorrectly.  Need to take it to my local train repair person.

Smart move!

Pat