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MTH Dreyfuss PS-3.  Runs 80% Loop OK.  Runs jerky on 2 areas.  Areas about 1 foot long.  When it hits the bad spots the amps jump up from approximately 3 amps to 6.2.

MTH Hiawatha PS-3 runs perfect for comparison. My other 20+ engines never behave poorly.   Trying to rule out track power.

I probably overfilled (I tend to) the smoke (about 20 drops).  With the loco smoke off I get perfect operation. On the loco motor, it sounds jerky, not smooth or steady when at bad area  Since it acts bad with smoke turned on I suspect electronic.  Let it dry out?  Or has someone experienced this?

Star wiring, ZW-L, up-to-date remote and TIU.  Signal all 10s.  Insulated power drops every 3 or 4 sections (approx. 36”).  

Last edited by Bryant Dunivan 111417
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Smoke fan or a possible short in the heating element.  Bad smoke fan motor can cause jerky issues but that 3 amp jump is typically a PV issue vice 5V PS issue.  So either it is binding and motor current going up, or that smoke element is shorting for some reason.

You can unplug just the smoke element and run it and see if it works with smoke on.  But you might have more then one issue going on.  G

Jon G posted:

If the motors and heater check out, its usually a bad ground through the harness.  

 

When I got home yesterday, the problem was still there, but much less pronounced.  The only thing that changed was time.  That being said, fluid was probably evaporated or ran off of the trace or whatever on a board or connector.  I will open the boiler at some point and take a look.

In the meantime, I will search post and see if someone has some internal pictures for reference.  I'm going to try to figure out if there is a path for the fluid to run to that causes issues.  Will update, when I am more informed.

Well, you might need to go back and revise what you are seeing.  IF this runs perfect all the time with smoke off, then more than likely it is the smoke unit.  Usually the fan motor is going bad and either too electrical noisy or drawing too much current.

If you are getting 3 amp spikes, that is not a poor ground, and would not be a smoke fan motor.  PS-3 can draw high current if the motor binds and the board raises current to try to maintain speed.  And of course there can be issues with data line connection between tender and engine since PS-3 is a 2 board system.

I am not sure what you really have, and troubleshooting assistance over the computer really requires an accurate input.  G

GGG posted:

Well, you might need to go back and revise what you are seeing.  IF this runs perfect all the time with smoke off, then more than likely it is the smoke unit.  Usually the fan motor is going bad and either too electrical noisy or drawing too much current.

If you are getting 3 amp spikes, that is not a poor ground, and would not be a smoke fan motor.  PS-3 can draw high current if the motor binds and the board raises current to try to maintain speed.  And of course there can be issues with data line connection between tender and engine since PS-3 is a 2 board system.

I am not sure what you really have, and troubleshooting assistance over the computer really requires an accurate input.  G

The OP was pretty accurate.  What I said recently was that the problem is better.  I did not do anything but let it sit all day not running.  I am speculating that excess fluid caused this problem and perhaps losing some the fluid made a difference.  Just speculation.   Something like, is it possible that a drop of fluid bridged 2 traces? Is it possible that a drop of fluid got into a plug that plugs into a pc board?   Should see some evidence when I open it up.

I was not looking for a final diagnosis on my part.  I have to get more information to input if I expect further help.  I was looking for the guy that has the exact same engine and the same problem.  That's all.

I can get further into the nitty gritty if I have to remove the boiler casing.  When I find out, I will amend the topic as solved, with what I had to do to help the next person.

 

 

When I arrived home last evening I thought a session with my Fluke Multimeter was in order. The 2 spots or areas I mentioned are on the ends of 2 switches with isolated frogs.  Adjacent to the frogs are 4" (or so) common rails.  The meter told me that the 4" rails leading to the frog are also isolated.  That leaves me with about 5 1/2" of no common to the wheels.  The jerky I mentioned is probably losing the voltage and picking it back up in that very brief sub-second it takes to reestablish power.  With the smoke unit on, the jerky symptom would probably be most visible as more current is being affected by the brief outage.

If it was the hot rail I could do something with the pick-up rollers.  Since it is the common rail, I would think the thing to do is solder a common wire to the 4" sections?  That should leave the frogs insulated for anti-derail with my DZ-2500 switch machines.  Does this sound like the sound solution?  I'm open to other thoughts.

Bryant Dunivan 111417 posted:

When I arrived home last evening I thought a session with my Fluke Multimeter was in order. The 2 spots or areas I mentioned are on the ends of 2 switches with isolated frogs.  Adjacent to the frogs are 4" (or so) common rails.  The meter told me that the 4" rails leading to the frog are also isolated.  That leaves me with about 5 1/2" of no common to the wheels.  The jerky I mentioned is probably losing the voltage and picking it back up in that very brief sub-second it takes to reestablish power.  With the smoke unit on, the jerky symptom would probably be most visible as more current is being affected by the brief outage.

If it was the hot rail I could do something with the pick-up rollers.  Since it is the common rail, I would think the thing to do is solder a common wire to the 4" sections?  That should leave the frogs insulated for anti-derail with my DZ-2500 switch machines.  Does this sound like the sound solution?  I'm open to other thoughts.

A picture of what you intend to do? If you connect the two insulated rails to common the switch will be constantly fighting to throw in both directions correct? So far all our issues with engines and switches/crossings have turned out to be loss of common due to the rubber tires. 

BobbyD posted:
Bryant Dunivan 111417 posted:

When I arrived home last evening I thought a session with my Fluke Multimeter was in order. The 2 spots or areas I mentioned are on the ends of 2 switches with isolated frogs.  Adjacent to the frogs are 4" (or so) common rails.  The meter told me that the 4" rails leading to the frog are also isolated.  That leaves me with about 5 1/2" of no common to the wheels.  The jerky I mentioned is probably losing the voltage and picking it back up in that very brief sub-second it takes to reestablish power.  With the smoke unit on, the jerky symptom would probably be most visible as more current is being affected by the brief outage.

If it was the hot rail I could do something with the pick-up rollers.  Since it is the common rail, I would think the thing to do is solder a common wire to the 4" sections?  That should leave the frogs insulated for anti-derail with my DZ-2500 switch machines.  Does this sound like the sound solution?  I'm open to other thoughts.

A picture of what you intend to do? If you connect the two insulated rails to common the switch will be constantly fighting to throw in both directions correct? So far all our issues with engines and switches/crossings have turned out to be loss of common due to the rubber tires. 

I'm listening.  Did you decide to live with the issues being caused by rubber tires, or did you do something to deal with it.

This is a frequently encountered but oft-unrecognized problem.  The non-derailer system only needs a short amount of insulated common rail.  Use a moto-tool to sever the rail, and connect the other portions of the outside rails to common.  When severing relatively short section of rail, I often squeeze a small amount of hard-setting glue (Ambroid) between the edges of the rails to keeo them in place and apart.

RJR posted:

This is a frequently encountered but oft-unrecognized problem.  The non-derailer system only needs a short amount of insulated common rail.  Use a moto-tool to sever the rail, and connect the other portions of the outside rails to common.  When severing relatively short section of rail, I often squeeze a small amount of hard-setting glue (Ambroid) between the edges of the rails to keeo them in place and apart.

Thank you for that.  That sound like a perfect plan.  I will look to do that this weekend.  When I implement the solution I will repost as solved.  I try to leave my messes solved with the solution for the next person that has the same issue.  Believe me, someone will.

Bryant Dunivan 111417 posted:
BobbyD posted:

A picture of what you intend to do? If you connect the two insulated rails to common the switch will be constantly fighting to throw in both directions correct? So far all our issues with engines and switches/crossings have turned out to be loss of common due to the rubber tires. 

I'm listening.  Did you decide to live with the issues being caused by rubber tires, or did you do something to deal with it.

Couldn't ever get the MTH harness wired A-B-A FT sets to work without stopping, so sold them. Eventually eliminated all the insulated rails for signaling on the layout, guests would bring their locos over with the dreaded 2 axle truck/1 axle with rubber tires and they'd continually have the same issue.

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