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Much to my amazement, my first shot at DCS with TMCC is working out well. Little hiccups with issues getting the wireless tethers connected on occasion, but overall, every locomotive was recognized and ran fine on the fixed and variable channels.

Challenged was first two tries with old reliable PW locomotives, and I don't think either was due to the DCS/TMCC. FA-2 AA diesels ran around the track great, no issue with the directional button on the DCS remote, but as soon as a connected the 3 passenger cars that came with the set, the FA-2s barely budged. Because everything else ran fine, I don't ascribe it to dirty track, weak voltage, or bad connections. I watched this engine pull 4 passenger cars with ease 50 years ago at my grandfather's. Just had the pick-up rollers replaced last week, and this was the first run. Could that be the issue?

My 2056 4-6-4 couldn't get out of neutral. Since the DCS got the FA-2s to change direction, I'm thinking this is a sticky E-unit and some WD-40 would help.

Any thoughts? I'm doubting myself because the conventional has always been bulletproof with TMCC causing the headaches.

Last edited by raising4daughters
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I suspect the issue is with the engines, not with having DCS running.  Did you clean and lube the FA? You could have grease on the armature shaft worm gear that is literally hard, the commutator on the engine is likely dirty, too and both could cause what you saw, especially a dirty commutator. .  If you search on here, or on you tube or the net, there is a ton of information about how to clean and lube PW equipment, it isn't hard.

With the steam engine, that is likely either the e-unit is stuck or it supports it the control arm is in the neutral position (the lever). Besides asking if the engine has been lubricated recently, with the e-unit I wouldn't use WD40, get yourself a can of tuner cleaner , which both cleans and lubricates, and try squirting that on the e-unit to clean the drums and fingers. 

Challenged was first two tries with old reliable PW locomotives, and I don't think either was due to the DCS/TMCC. FA-2 AA diesels ran around the track great, no issue with the directional button on the DCS remote, but as soon as a connected the 3 passenger cars that came with the set, the FA-2s barely budged. Because everything else ran fine, I don't ascribe it to dirty track, weak voltage, or bad connections. I watched this engine pull 4 passenger cars with ease 50 years ago at my grandfather's. Just had the pick-up rollers replaced last week, and this was the first run. Could that be the issue?

I wouldn't be so quick to dismiss voltage.  Measure the actual track voltage when you're running.  Also, if the engine has been stashed away for 50 years, a general maintenance is called for.  Check the brushes, clean the commutator, and lub everything.

My 2056 4-6-4 couldn't get out of neutral. Since the DCS got the FA-2s to change direction, I'm thinking this is a sticky E-unit and some WD-40 would help.

Do NOT spray WD-40 on your E-Unit, that will only create more problems!  A totally dry lubricant is OK, but typically they don't need any lube.  Anything like WD-40 will cause the plunger to start sticking.  The E-Unit depends on gravity, and just the weight of the plunger is what makes things go.

Thanks everyone.  @gunrunnerjohn came up with a logical idea. Lo and behold, I'm only getting 15.5V on my outer mainline which is powered by two LW transformers connected to the two variable TIU channels.  I think that's the main culprit here.  The FA-2s WERE able to pull 4 MTH Rail King O27 Madisons around the track with no issue, so the engine appears to be in good repair. They use some pretty low demand bulbs.

They're severely challenged, however, by the consist of 3 PW O27 Lionel Lines passenger cars and 2 more matching WBB Luxury Lions. It pulled the PW cars fine, but but adding the 4th and 5th caused the wheels to spin. The modern WBB's have really bright bulbs and I think the power draw of these 5 cars on lower-than-needed voltage is the problem.

I'm going to check all my connections on both power districts and see why I'm only getting 15.5V on each from the LWs. They're capable of 19V, so guessing I've got some wiring or connection problems in places.

BTW, my inner main is powered by two PW RW transformers which have slightly lower power than the LWs, but I've got a 17.5V everywhere on that mainline.

I'll also take advice from @John H and see what kind of voltage I get with the TIU out of the loop.

Thanks all.

Last edited by raising4daughters

So, at GRJ's suggestion, I checked track voltage on my two variable channels (connected to a single mainline in blocks). Although I set the DCS remote to 18-18.5V, actual track voltage was only at 15. I checked every track segment and all were the same (except 2 that I think I need to replace, but I digress), so 3-3.5V less than what I was requesting via the handheld.

I raised the voltage on the handheld to 20.5 and was able to achieve 17-17.5V actual track voltage. My first thought was that I must have a wiring problem; however, my track voltage matches perfectly to the TIU output terminals. No matter what I measure at the TIU variable channel output terminals, I get the same voltage around the entire mainline, so that tells me my wiring is good.

So, the first thing this electrical neophyte thinks is that this is normal OR, more likely, the problem is in the TIU, but on both variable channels???

Each LW transformer is pushing 18.6V into the TIU, no issue there.

Thoughts, suggestions?  Can I just set the DCS remote at 20-22V to get my needed 17-18V at the track or is that going to stress the TIU?

BTW, even when there's 17-17.5V on the track, the Alco AAs are struggling with the 5 lighted passenger cars, so I think I'm going to look for some LEDs and see if that solves that problem. Other suggestions?

Last edited by raising4daughters

What's the output voltage of the LW when you measure it directly?  The TIU "assumes" 22V input when computes the voltage shown for conventional running.  However, if the LW is only putting out 18V, then the TIU will lie to you at a 20% over statement of the voltage.

Another point.  Under any load, the TIU drops a volt & a half or so through the variable channels, however if you measure the output no-load, it varies very little from the input.

Transformer output on the left and TIU output on the right with no external load.

Transformer output on the left and TIU output on the right with 2A external load.


Note that the TIU drops about a volt and a half with any significant current flowing through the variable channels.

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What's the output voltage of the LW when you measure it directly?  The TIU "assumes" 22V input when computes the voltage shown for conventional running.  However, if the LW is only putting out 18V, then the TIU will lie to you at a 20% over statement of the voltage.

Another point.  Under any load, the TIU drops a volt & a half or so through the variable channels, however if you measure the output no-load, it varies very little from the input.

Note that the TIU drops about a volt and a half with any significant current flowing through the variable channels.

Thanks. Yes, I did notice your latter point, about a 1.5V drop under load, so that jives with my experience.

The LW's output at the transformer is 18.6V.  I get the same right at the input to the TIU, so (as expected) no drop in the short wires to the TIU.  On the output side of the TIU, that's where I'm seeing 15V even though the DCS remote is asking for 18V.

If I understand you right, I should assume I'm only going to get actual voltage of 80% of what I dial up on the DCS remote, so if I want full throttle from the LWs, I should set around 21-22V.  Correct?  Wondering how or if I missed that in Barry's DCS Companion book.

If you have an 18.6 volt input with no load, then to get max voltage, just crank the remote up to 22V.  It's in Barry's book, but it's a fairly long explanation as I recall.  Sometimes there's so much detail in his book that it's hard to find a simple fact.

John, wanted to circle back and thank you. I'd have been pulling my hair out wondering why I was seemingly experiencing voltage drop inside the TIU.

Cranked her up to 22V and got 18.5V on the tracks to match the 18.5V at the output terminals of the transformers. I checked every piece of track and was spot on except one which looked like it had bad/loose connections. I fixed 'em and now they're all up to 18.5V.

Love to hear success stories.

Well, with the voltage problem solved, I tried running 3 smaller PW 2400 series passenger cars along with a WBB 2-car add-on for a total of 5 lighted passenger cars with my a PW 2056 Hudson and with 2023 UP Alcos. Both have been recently serviced. New brushes on the Hudson.

On my layout which, admittedly, has fewer straightaways, they cannot get enough momentum going. Mostly wheel spinning. They're fine, however, pulling 10 freight cars with a lighted caboose. No struggles at all and can pull them at way lower than max voltage. I bet I could add 5 cars without issue.

The loop is about 80' of track with 40' powered by one LW and the other 40' by another LW.  I figured that to be more than enough power. With no load, I get the full 18.5V everywhere on the track. No grades, just flat table top with a U-shaped layout that's pretty darn level.

Another data point: On the same loop, I'm not having any issues with DCS and TMCC modern locomotives pulling modern Rail King passenger cars.  Seems like the issue is limited to the PW and WBB passenger cars.

Could there be something going on in, say, one car that's drawing too much power? Any other suggestions or tips? Time to get some LEDs?

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