Trouble on the Tracks - ZW Controller Problem

It would be helpful to know what you have done to diagnose the problem with your controller and transformer set-up; such as checking for loose wiring connections, shorts to ground, maybe swapping connections between controller and transformer, and/or checking AC voltages at different points in the electrical path from the controller thru the transformer to the track starting at the source.

After checking for loose connections at the power source and for electrical shorts between power and common with a multi-meter, I suggest checking AC voltages at different points- with track wiring connected and then disconnected.

Thanks Steve. I will do those things and see what I find.

I opened up the ZW and did my best to compare by sight the wiring on the right with the non working left. Nothing seemed amiss, no loose wires etc. Both accessory voltage throttles work...just the right track throttle is inoperable. I switched bricks and the right continued to work while the left did not.

When you switched brick connections to the controler, did the bricks remain connected to the same track wiring sections or did those swap too?

I only have one set of wires to the track right now, connected to the left throttle and working fine. I switched the wires over to the right and no luck.

I sounds like the problem is probably in the controller.  Whether you can fix it yourself would depend on what you know or are willing to learn about diagnosing and repairing electrical/electronic circuits.  Do you have a multi-meter and soldering tools/skills?  Or you may decide to have someone else fix it.  Either way, if you don't already have a spare transformer/controller you might consider getting a spare if you want to continue running trains until the ZWC is fixed.

For your reference - ZW C electrical wiring diagram attached

@SteveH posted:

I sounds like the problem is probably in the controller.  Whether you can fix it yourself would depend on what you know or are willing to learn about diagnosing and repairing electrical/electronic circuits.  Do you have a multi-meter and soldering tools/skills?  Or you may decide to have someone else fix it.  Either way, if you don't already have a spare transformer/controller you might consider getting a spare if you want to continue running trains until the ZWC is fixed.

Thanks for all the tips and replies. Regarding a spare transformer, my layout is basically a 12’ by 12’ circle. The ZW seemed a bit overpowered for it, meaning the train was flying but the throttle wasn’t up high enough to power the passenger cars to full illumination. Would an MTH Z 1000 ($129.95) be a sufficient backup?

Running conventionally, any transformer will have essentially the same behavior where this same Locomotive runs at less than full speed but your passenger cars lights are not at full brightness.  Legacy, LionChief, LC+, etc. overcome this problem by supplying a constant 18V to the track and controlling the engine speed remotely via electronics in the Loco.

But, yes, the MTH Z 1000 should be sufficient for your current set-up, however there may be better alternatives for you.  One thing to consider is that MTH is going out of business, so... warranty? parts??  Other things to consider would be in the future, how may trains might you be running at the same time and do you want to have one or more separate outputs for accessories.  If you only want your back-up transformer to run one train at a time and want a dedicated accessory output The Lionel CW 80 might be a good choice.  In fact there is one listed for sale now here on the forum ( and if you're wondering, I don't know or have any affiliation with the seller).  https://ogrforum.com/topic/lionel-cw80

Good Luck!

@SteveH posted:

Running conventionally, any transformer will have essentially the same behavior where this same Locomotive runs at less than full speed but your passenger cars lights are not at full brightness.  Legacy, LionChief, LC+, etc. overcome this problem by supplying a constant 18V to the track and controlling the engine speed remotely via electronics in the Loco.

But, yes, the MTH Z 1000 should be sufficient for your current set-up, however there may be better alternatives for you.  One thing to consider is that MTH is going out of business, so... warranty? parts??  Other things to consider would be in the future, how may trains might you be running at the same time and do you want to have one or more separate outputs for accessories.  If you only want your back-up transformer to run one train at a time and want a dedicated accessory output The Lionel CW 80 might be a good choice.  In fact there is one listed for sale now here on the forum ( and if you're wondering, I don't know or have any affiliation with the seller).  https://ogrforum.com/topic/lionel-cw80

Good Luck!

Thanks Steve. Good point about MTH. I actually have a non working Lionel CW 80. I’ve been reading many posts here about how they’re not really worth sending out for repair when you factor in shipping costs. Also, the green light comes on so it doesn’t appear to be the fuse, according to what I’ve read. I opened it up but didn’t see anything weird. I wanted to open up the brick but it had screws I’ve never seen before, I don’t know what they are.

maybe you could post a picture of the screws?

Didn't the early remake of the ZW have a program? I think I remember something like this happening to someone and it just had to be reprogrammed.  I could be wrong but do you have the owner's manual still? I'd look into that first before you go out and spend money.

@E-UNIT-79 posted:

Didn't the early remake of the ZW have a program? I think I remember something like this happening to someone and it just had to be reprogrammed.  I could be wrong but do you have the owner's manual still? I'd look into that first before you go out and spend money.

Hmm I tried the recalibration but the red light didn’t flash 5x per the instructions. I got out the voltage meter and discovered that my A terminal, the one with the issue, registers 18 volts in the off or on position. All my common posts appear to be ok so it’s just that A post. I don’t know what this means though! 😎

@Madlove posted:

Hmm I tried the recalibration but the red light didn’t flash 5x per the instructions. I got out the voltage meter and discovered that my A terminal, the one with the issue, registers 18 volts in the off or on position. All my common posts appear to be ok so it’s just that A post. I don’t know what this means though! 😎

Neither do I as I never owned one of the news zw's but I was at someone's house one night and they were having a problem with it and we figured out it was some kind of programming issue but I can't remember what it was it was too many years ago.

Madlove,  Here are some clarifying questions:

1) When you measure 18VAC at the A terminal, where is the other Meter probe connected?

2) When measuring the 18VAC in "the On and Off position, do you mean the Throttle?

3) When you say the Common posts appear to be ok, how did you make this determination, please include details of meter connections and meter settings?

@SteveH posted:

Madlove,  Here are some clarifying questions:

1) When you measure 18VAC at the A terminal, where is the other Meter probe connected?

2) When measuring the 18VAC in "the On and Off position, do you mean the Throttle?

3) When you say the Common posts appear to be ok, how did you make this determination, please include details of meter connections and meter settings?

Hi Steve

1. The other meter probe was on the common post directly above A.
2.  Yes, I meant the throttle.

3. I determined all the other posts were working by interchanging the common posts while contacting B C & D. For example, D worked fine while making contact with all four of the common posts. Same for B and C. The results for A were the same when I tried the other 3 common posts, so I’m assuming something is wrong with just the A post path.
All the readings were 18 volts, including the wacky one for A.

I would assume you have tried completely unplugging 120V line power from the controller and bricks for 30-60 seconds or more.  Have you tried using the Reset on the controller?

@SteveH posted:

I would assume you have tried completely unplugging 120V line power from the controller and bricks for 30-60 seconds or more.  Have you tried using the Reset on the controller?

I have unplugged. I also tried pushing the reset button but the red light did not flash per the instructions so either that’s another problem or the same problem.

Well, that's the extent of what I think I can help you with.  Unless someone else here has any suggestions, it might be time to send the ZWC in for repair.

Others have more knowledge, but I know that the ZW-C has a gear system, one gear on a throttle handle, the mating gear on a potentiometer. The ZW-C was mfg'd with plastic brackets holding the potentiometers - and this plastic bracket could break, separating the gears for a throttle. I understand Lionel offered metal replacement brackets, but that they are no longer available. I would assume, but don't know, that the way the throttle handle's tactile feel while moving would feel different from a throttle handle whose gear was still mating the pot.

Maybe this post will jog the memory of one of the more knowledgeable forum members.

If there are metal replacements, I would be interested, as I have a ZW-C in storage for future use when my layout gets a bit larger. EDIT - I ordered two brackets from Lionel today (need two for one ZW-C) - order info below

In the same situation with ZW-C problems as Lionel mfg'd, I believe there also a situation when using Legacy control of the ZW-C - the ZW-C could misinterpret a command sent to an engine as an emergency shut down (i.e. as if you had hit the HALT button on the Legacy CAB-2). Again, Lionel offered a revised PROM module you could install at home, but by the time I found out about this, these PROMs were no longer available. Would be interested in a revised PROM module also. Edit - emailed Lionel today to see if PROM or PIC still available.