Legacy PRR K-4

I can't think of a function that would do that.  Have you tried a TMCC Reset?  If that doesn't do it, I think something is amiss, mine doesn't do that.

1. Slide the Program Run switch to the PGM position.
2. Plug in and connect your LEGACY (or TMCC) Base.
3. Place your locomotive on the track, then power up the track.
4. Press ENG and enter the locomotive’s ID#.
5. Press SET.
6. Turn off track power and wait ten seconds.
7. Slide the program run switch back to the RUN position.

All settings should be back to factory defaults.

I have run the Legacy K4 and noticed that with the smoke unit turned off the fan still comes on at every chuff. Your best bet is to get it repaired - it was driving me nuts as well.

I purchased the prewar K line K4 with legacy speed steps and cruise. No issues.

Wish Lionel would have put the smoke deflectors on the K line re-issue.

It did not do this the first run. I assumed it started after my mindless session of button pushing. If reset does not work I can see the plug going to it and will just unplug it as I do not use the smoke feature.

Some Lionel engines the smoke fan runs all the time, even if the smoke switch is off, the off only turns the heaters off. Maybe this is one of them?

I believe Chuck is saying what I am saying, the motor always runs, it probably was quiet and a few laps around the layout... then the motor bearing began to wear... good news is I believe they have the new assemblies in now.

I took my Legacy K-4 out and indeed the motor does run, it's just very quiet, and I never noticed it running.

Sounds like it needs a new motor.

You can try oiling that one, many times that will do wonders for them.

Have you tried AUX1, 8 to shut the smoke unit off by the remote?

If the switch is off and it still runs, the DC fan has power via another path.  If this is the new RCMC Legacy board, I believe it may operate a little like MTH in that power is available and Ground is controlled via the board FET.  With switch in off, your not suppose to be able to turn smoke on in the command environment at least according to the Legacy K4 manual.  G

Some function is controlling it, it only runs when going forward and shuts off when at sitting and in reverse. It also comes on from time to time when stationary. Loco has only run back and forth on ten feet of track. I reset the loco and put the cab number in and that worked. It seems there was a number on my older Lionel TMCC units that put them back to factory settings. I still have a list of these for my older engines. Has this changed with these newer models?  

What you have going on with that smoke unit is odd to say the least, and something I've never seen posted before.

The smoke unit should either work or not, the direction of travel shouldn't matter. Theres something really amiss here. I'm curious as to where you purchased it? I'd consider returning it.

Having said that, there are instructions for reprogramming your locomotive to restore features, near the back of the owners manual. I believe it is also listed in the table of contents at the front of the manual.

Problem solved. I did try a reset as described in the manual and it changed nothing. Opened it up and there are two small smoke units that are identical , maybe one for the stack and one for the cylinders .  Two screws and a plug on each and they are now removed as I don't use the smoke anyway. The flashing cab light also went away the manual says 3 blinks was a smoke fan problem. Very small cheesy motors and I am guessing that they have dry bearings from lots of shelf time in the hobby shop.  I Will oil them up on the bech and prove that out and save them in case I decide to sell it at some point. Thanks for all the input from everyone. I would normally have returned it but I got a great deal on it.  Rick