6 ohm resistors

It was the reverse....6 to 8 OHM resistor.

What train are you working on?

I am working on a Lionmaster sd90  6-28254  .   The problem I am having is that the smoke unit does not shut down when pressing the no smoke button on my cab 2.  Or if does turn off only momentarily.  I was thinking that if it has the original 6 Ohm resistor it might be affecting the smoke regulator  and causing the problem.  It smokes great but I can only turn it off using the bottom switch.  If I do need to change out the 6ohm resistor I need to know what wattage the 8 ohm resistor should be.

Thanks    Marty

YES change the 6 Ohm resistor to 8 but the damage may be done.

Remember Ohm's law? A 6 Ohm resistor draws more current than an 8 Ohm resistor given the same source. Being your train uses a smoke regulator module and the extra current and power that a 6 Ohm resistor causes can damage the regulator. Lionel figured this out and recommended people to change to 8 Ohms BEFORE they damaged the regulator.

You may have damaged your regulator and while Lionel pulled many of these parts- I found the other day working on a similar Lionmaster SD80 that Lionel listed that part.

https://www.lionelsupport.com/...TOR-ES2-LM-SD80-SD90

https://www.lionelsupport.com/SMOKE-RESISTOR-8-OHM

It's possible without too much trouble to rewire and eliminate the regulator when they fail.  By wiring directly to the smoke output of the R2LC, and using a standard TMCC 27 ohm resistor, you can remove the regulator and it's problems.

Thanks for the replies.  I will try to rewire first and if that does not work order the regulator.

Marty

@martind posted:

Thanks for the replies.  I will try to rewire first and if that does not work order the regulator.

That ship has sailed, the regulators are unobtainium, Lionel declared all of them obsolete and removed them from their parts site!

If the regulator is bad, the solution is to rewire for direct connection and replace the resistor with the 27 ohm model.  Don't forget to run the smoke output through the existing smoke switch so you can manually disconnect the smoke function.

@gunrunnerjohn posted:

That ship has sailed, the regulators are unobtainium, Lionel declared all of them obsolete and removed them from their parts site!

If the regulator is bad, the solution is to rewire for direct connection and replace the resistor with the 27 ohm model.  Don't forget to run the smoke output through the existing smoke switch so you can manually disconnect the smoke function.

John, that's why I posted the link- oddly I found one regulator that had NOT been removed- maybe because it's part of a complete harness.

I'm not saying your solution of rewiring to the smoke TRIAC output of the R2LC and the 27 Ohm requires resistance for that rewire situation is not possibly a better long term solution.

Again, just my own comments and thoughts are- if you want/need a regulator for a TMCC engine (one that uses the typical R2LC C08) here is a source of one that did not get pulled.

https://www.lionelsupport.com/...TOR-ES2-LM-SD80-SD90

Edit: and again, if you go down this road to replace a failed regulator- be sure to use an 8 Ohm resistor rather than an original 6 Ohm to hopefully extend the life of the regulator.

@Vernon Barry posted:

John, that's why I posted the link- oddly I found one regulator that had NOT been removed- maybe because it's part of a complete harness.

I'm not saying your solution of rewiring to the smoke TRIAC output of the R2LC and the 27 Ohm requires resistance for that rewire situation is not possibly a better long term solution.

Again, just my own comments and thoughts are- if you want/need a regulator for a TMCC engine (one that uses the typical R2LC C08) here is a source of one that did not get pulled.

https://www.lionelsupport.com/...TOR-ES2-LM-SD80-SD90

Edit: and again, if you go down this road to replace a failed regulator- be sure to use an 8 Ohm resistor rather than an original 6 Ohm to hopefully extend the life of the regulator.

That's interesting, but if you spend $30 on that and find out it's like the bunch I got from Lionel parts several years ago that were all bad, you're out $30.  OTOH, for free with a little wiring, you can fix this problem permanently.  Well, maybe $2 for the smoke resistor change...   I know I wasted money on the smoke regulators, but I don't do it anymore.  If the smoke regulator is bad on a TMCC locomotive, I rip it out and wire it directly.

Now, if you have an early Legacy locomotive, you have no choice but to hunt for a regulator, the rewiring fix doesn't work for Legacy.

John,

I want to make sure I get this correct

When by passing the smoke regulator:

1. do you remove all wires and plugs?

2. To which pin on the R2LC do you connect the hot from the smoke unit?

3.  Is a wiring diagram available I have checked all the diagrams I have and none show the R2LC

4.  do you solder to the R2LC board or the pin itself?

thanks,

Marty

See answer embedded.

@martind posted:

John,

I want to make sure I get this correct

When by passing the smoke regulator:

1. do you remove all wires and plugs?

I remove the regulator and it's associated wires.

2. To which pin on the R2LC do you connect the hot from the smoke unit?

Pins 5 & 6 of the R2LC are the smoke output.  Many motherboards have a smoke connection, if so I use that.  If not, I wire to either the socket or the motherboard, don't wire to the R2LC directly.  If it's wired to the R2LC, you need a soldering iron to remove the board in case that's necessary.

3.  Is a wiring diagram available I have checked all the diagrams I have and none show the R2LC

I know of no wiring diagram, I've never made one.  Basically, you wire from the R2LC smoke through the smoke switch and to the hot lead on the smoke unit.  It's simple enough that I never felt the need for a diagram.

See the board pinout document attached for more info.

4.  do you solder to the R2LC board or the pin itself?

No, see above.

thanks,

Marty

Attached is a document with all the connections to the main TMCC/Railsounds boards.

TMCC-RailSounds Board Pinouts.pdf

John

thanks that is exactly what I need.

Marty

Not to muddy the waters but this post below speaks to a problem in the R2LC triac circuit that turns power to the smoke unit on and off. To me it has nothing to do with the AC reg. The smoke unit is still getting power when it shouldn’t.

@martind posted:

I am working on a Lionmaster sd90  6-28254  .   The problem I am having is that the smoke unit does not shut down when pressing the no smoke button on my cab 2.  Or if does turn off only momentarily.  I was thinking that if it has the original 6 Ohm resistor it might be affecting the smoke regulator  and causing the problem.  It smokes great but I can only turn it off using the bottom switch.  If I do need to change out the 6ohm resistor I need to know what wattage the 8 ohm resistor should be.

Thanks    Marty

Rod

@Rod Stewart posted:

Not to muddy the waters but this post below speaks to a problem in the R2LC triac circuit that turns power to the smoke unit on and off. To me it has nothing to do with the AC reg. The smoke unit is still getting power when it shouldn’t.

Well, you muddied the waters.   This model uses the smoke AC Regulator which receives the serial data and controls the smoke heater.  The R2LC triac is not controlling the smoke.

Rod

Thanks for the suggestion.  I have some new 8 Ohm resistors on order.  I will replace the current resistor when they come. I have some extra R2LC boards and try that before taking out the regulator unit. 

Marty

Looks like I am back to either replacing the smoke regulator or wiring directly to the R2LC.

Marty

@gunrunnerjohn posted:

Well, you muddied the waters.   This model uses the smoke AC Regulator which receives the serial data and controls the smoke heater.  The R2LC triac is not controlling the smoke.

I am familiar with the function of the ACRG. But I thought the R2LC still acts as the master on-off control for power to the entire smoke unit circuit even when the ACRG is used. At least that’s how I have seen it hooked up in a Lionel drawing.

Rod

@martind posted:

Rod

Thanks for the suggestion.  I have some new 8 Ohm resistors on order.  I will replace the current resistor when they come. I have some extra R2LC boards and try that before taking out the regulator unit.

Marty

Trying a spare R2LC is the first thing I would probably do. If that doesn’t work you haven’t lost anything.
Rod

@Rod Stewart posted:

I am familiar with the function of the ACRG. But I thought the R2LC still acts as the master on-off control for power to the entire smoke unit circuit even when the ACRG is used. At least that’s how I have seen it hooked up in a Lionel drawing.

Rod

Nope, the ACRG is the only thing that is controlling the smoke resistor.  I've never see a diagram that states otherwise, but I can't say that one doesn't exist.  However, I can say if one exists, it's incorrect.

Here's a couple of Lionel wiring diagrams with the smoke regulator.

Lionel TMCC F3 Wiring Diagram.pdf

6856_AlcoS2SwitcherWD.pdf

Also, I've personally wired a few of these in upgrades years ago.  That was before I found out how failure-prone they were, now I don't bother.

However, for early Legacy, they're the only game in town, and those go bad frequently as well.  I've even gone to the trouble of creating a crutch board for failing Legacy regulators since there is no option to re-wire them.  The Legacy smoke regulators frequently fail by dropping their output below what would produce smoke, but still have an output controlled by TMCC/Legacy.  So, I built a little board to drive the smoke unit from this low power output so I could still have command controlled smoke for early Legacy models.

A Smoke Control Relay For Special Occasions

Thanks grj for posting those wiring diagrams. They do indeed seem to show the power to the ACRG connected directly to the rollers, not pin 5/6 of the R2LC.

I don't have access to all my mod notes here in Sweet (winter) Home Alabama, but I am quite sure I rewired a couple from my roster to bypass the ACRG, and the R2LC was controlling overall smoke unit power. I say this because it still worked that way after the mod. One may have been Lionmaster Cabforward 4294, but its too far back to recall exactly. Maybe this was done only for steam? Don't know why it would be different though.

Regardless, the OP really has nothing to lose by swapping in a different R2LC for tryout. And if there is still a problem then back to bypassing the ACRG per grj's notes above. The smoke switch hot wire will have to be moved to the R2LC smoke output though as suggested above, so that the Cabx can control the smoke. It will be interesting to hear the followup!

Rod

@Rod Stewart posted:

I don't have access to all my mod notes here in Sweet (winter) Home Alabama, but I am quite sure I rewired a couple from my roster to bypass the ACRG, and the R2LC was controlling overall smoke unit power. I say this because it still worked that way after the mod. One may have been Lionmaster Cabforward 4294, but its too far back to recall exactly. Maybe this was done only for steam? Don't know why it would be different though.

Rod, I have no idea of what you were seeing or how it was wired.  I know I've worked on dozens of these regulator circuits, and I've never seen one wired to the smoke output.  In point of fact, that would be a major issue as the smoke output from the R2LC is half-wave (positive peaks) of the track power.  Sending chopped waveforms into another triac is not a good idea.  Also, there would be no point in sending it through two regulators.

Here's the Lionel diagram for the standard wiring of the Smart Smoke for steam using the regulator.  The only connection to the R2LC is the serial data and chuff switch.  This is generally what I've found in all the steam I've worked on with the regulator.

@Rod Stewart posted:

Regardless, the OP really has nothing to lose by swapping in a different R2LC for tryout. And if there is still a problem then back to bypassing the ACRG per grj's notes above.

This is certainly true, it only takes minutes to swap out the R2LC.

martind; In case it helps at all attached is a couple of internal pics from sister engine CP #9108 from my roster. Should be identical because when I searched parts for yours the CP version came up.

The R2LC is super easy to get at it turns out. I know I mapped out the mobo pinouts in rough but I don't have that info here. You will have to ping your mobo to see which pin belongs to R2LC pins #5/6, for rewiring so the smoke triac controls on-off. The mobo is 691 MB00 18A just for info.

Rod

Rod and John, thanks for your help you guys provide great information.   Lastly, if I understand correctly, the smoke unit is wired  to pin 5 or 6 on the R2LC  and the black wire goes to ground on the body.  I can also wire the hot through the switch for smoke on off or is that redundant?

Marty

@martind posted:

I can also wire the hot through the switch for smoke on off or is that redundant?

Actually, you want that switch in the circuit.  If something goes wrong with the R2LC triac, the switch turns things off.  Also, for conventional running, that's the only way to turn off smoke.

@Rod Stewart posted:

The R2LC is super easy to get at it turns out. I know I mapped out the mobo pinouts in rough but I don't have that info here. You will have to ping your mobo to see which pin belongs to R2LC pins #5/6, for rewiring so the smoke triac controls on-off. The mobo is 691 MB00 18A just for info.

And you didn't put that info in your motherboards document?  For shame Rod!

Attached is a side by side comparison of Lionel's older diesel mobo 691-PCB1-11E (from my motherboard connections powerpoint) and the one that you likely have in that engine 691-MB00-18A. 18A appears to be a newer version of 11E.

You will note in the lower right corner of 11E pins 4 and 5 of the 5 pin header are identified as SMU power. All headers are the same on 18A so perhaps the same pins on it are SMU power. There is of course no guarantee, but those are the first ones I would check. In fact if there are wires connected to those pins it would be interesting to trace where they go??

And you are correct grj; I should add 18A to my powerpoint someday!

Rod

@Rod Stewart posted:

And you are correct grj; I should add 18A to my powerpoint someday!

I have a bunch of motherboards  you could add.

@gunrunnerjohn posted:

I have a bunch of motherboards  you could add.

How many are we talking about? Are they loose? Are the pins identified; that's the biggest part of the job? I don't mind doing all that but I would have to borrow the boards in question, then return them.

Rod

I probably have at least 50 motherboards, both sound, engine, and full up three-socket boards.  I suspect there are around 8-10 that are not in your database.  FWIW, I find that document very useful.

@gunrunnerjohn posted:

I probably have at least 50 motherboards, both sound, engine, and full up three-socket boards.  I suspect there are around 8-10 that are not in your database.  FWIW, I find that document very useful.

It has turned out to be more useful than I ever imagined; glad you like it! Back at least 10 years ago I smoked the mobo, R2LC and the DCDS in a 2000 era Mountain steamer. BoxcarBill had all the needed boards plus I bought a few others from him later that he had spares of. (I recall he made me a good deal on them) That's how the whole thing got started because I found wire tracing without was a big pitb.

If you have duplicates that you don't mind loaning out for a while I could get them traced out and added, then shoot them back to you. We are in Gulf Shores Alabama until the end of the month, so shipping would be pretty reasonable. Shoot me an email offline to discuss further if you like.

Rod

Success!!!!  Thanks to John, Vern and Rod for your help with this smoke unit in the Lionmaster sd90.  I disconnected the regulator rewired the smoke unit and replaced the resistor with a 22ohm, smoke is good and turns on and off when triggered from the cab 2.

Marty

Love a project that ends on a happy note!

Rod

Great, love success stories.