Lionel 6-38000 (CCII TMCC Streamlined Hudson) - Smoke Unit Not Working.

I did a Reset... no dice.  No broken wires/switches.  Has anyone had experience with these… and/or common smoke unit problems? 

Found these Parts

SEMI-SMART SMOKE UNIT (ALT# 6308085200) ß unavailable



Any comments, advise and/or opinions are greatly appreciated (I don’t understand the electronics as well as I should… but, I’m getting there).  I do have a very good volt/Ohm meter.

Thank you,


Original Post
Norton posted:

Most of the time its the AC regulator that goes. I would order one of those and couple of 8 ohm resistors. If you turn off the sound (Aux1 4, repeat) can you hear the fan as the engine moves?



Yes, I can hear the fan... thanks!  Learning every day.  Fortunately I have a home built test station and the engine is on rollers... so, it's easy to listen for and clearly hear the fan.

Does this narrow down the potential culprit?




It could still be either part mentioned but before ordering check the resistor with an ohmmeter. It should read 8 ohms.  With the shell off, you should be able to see two tiny screws just behind the stack. Those are what the resistor is connected to. If it reads anything above 12 ohms or so the resistor has opened up. It may only be that. If it reads about 8 then the AC Regulator is likely bad. If thats the case then order resistors too as they will eventually burn out. They are cheap compared to shipping so include them with the order now. Many other engines use the same resistor.



Did this ever work or did you just receive it like this? If the latter it looks like someone put the wrong resistor in there. 27 ohm resistors are commonly used on smoke units connected directly to the track and also those connected directly to the R2LC feature pin. If it still reads 27ohms save it for another engine.


I bought it *used* a few months ago (very good price... and, I already had a PT Tender) and just got around to testing it.  Everything works perfectly except for the smoke... and, it had definitely been opened before.  I closed it back up and didn't remove the resistor... but, ordered (2) 8ohm resistors.  I did peak at it and it looks like the resistor is  inside a steel coil.  I tested it several times... all @27ohms ...Make sense?

The 27 ohm resistor won't some at all on the regulator equipped models, so that's doubtless one of your problems.  Of course, the original owner may have replaced the good 8 ohm resistor thinking it was bad when it was really the voltage regulator.  You'll find out when you get the correct resistor in there if it smokes.

Finally, Lionel sent the resistors... 18/19 days wow!  Anyway, works beautifully now... except with the shell on!!!

Thrice, I have removed the shell and it works... thrice I have placed the shell on... no smoke.  the fan *always* works... shell on or off.   I cannot find a short anywhere... do I have to un-bundle the tied the mass of wires to trace this out?  Going to take a break and fix the light switch in the kitchen.

Any insight is greatly appreciated... THANKS!!!



Well... looks good now.  I put a piece of electrical tape between the stack and the screw heads of the resistor... it's working.   I have no idea if that was the problem or not as I am not able to tell if the stack gets pushed down to the resistor screw heads or not when the shell is on... all I know is that now it works.  While doing the fourth go over I lubed the fan, bored the fan intake and put new batting in... smokes like big mama now!  


If tape is fixing it, you need to look closer as it'll wear through the tape with time.  If the resistor is being shorted to the frame, it'll likely cook the voltage regulator, that's $30 + some work to install it.

I'm with you on that... it's 3 or 4 layers electrical tape (rolled over on itself).  I could grind down the resistor screws or the stack so they don't touch... I can't figure out WHY they touch in the first place.  Of course my eyesight is not what it used to be... maybe I need to move to G scale.

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Dave Garman

OGR Publishing, Inc. PO Box 218, Hilliard, OH 43026 330-757-3020