Aux Power for Fastrack Switches

@tumbleweed56 posted:

I am guessing there must be something wrong with the aux wiring in the switch, since it works fine with track power.  Any ideas on where to start troubleshooting the aux wiring for this switch?

This is a known and very widespread problem.  A large number of switches were wired incorrectly when they were assembled at the factory.

Follow this link:

     Fastrack remote track-switches sometimes having their terminal blocks assembled incorrectly (1/21/21) | geysergazer

Mike

Thanks Mike for the link to the thread.  I had no idea, what a pain.  

I doubt the problem of loss track power is the Aux power source to throw the switch, especially if 4 others work.  The lantern is on because the switch is getting Aux power to throw the switch.

The problem with no track power is probably with the two internal switches or contacts inside the track switch that change the track power from a curved rail to the straight rail or vice versa on the movable rail section that is rotated when throwing the track switch.

Although Lionel and Marx track switches are different this same above operation has to happen.  When I have track power loss on one of my Marx 1590 switches, I use fine sand paper to clean the two track switch internal contacts can be seen when looking down on the switch on the end of the switch with one rail coming in.  Lionel track switches are different but do the same thing to switch power from the straight rail to the curved rail or vice versa.

The brass piece, seen below, contacts one of two rivets below the brass piece and can be cleaned with fine sand paper.  The two rivets are on the rotating track section

Marx 1590 switch

Lionel 022 switch showing center rail contact springs and connecting pins - I bet you will have take the switch apart to clean

Charlie

This sounds to me as if the terminals may actually be oriented as labelled since the mechanism operates correctly wired to Aux power.

With the jumper removed, Aux power only feeds the turnout's internal electronics, LEDs, remote, and motor.  When the turnout is powered via the Aux Power terminal, power to the rails is intended to be supplied by adjacent connected track sections.  However, it sounds as if the center rails on the turnout aren't getting a good connection through the combination of track mating pins connected to adjacent track sections and/or through the internal connection bus array within the switch.

A continuity check with an Ohmmeter would confirm poor connections at and inside the switch may be the cause of the loss of track power.  To avoid false meter readings, it's best to disconnect the switch from adjacent track and all wired power and ground connections.  When measuring from one end of the switch to another, there should be less than a few Ohms resistance end to end from center rail to center rail.  The same should be true for the outside rails from one end to another.  Check all three ends of the switch, center and outside rails.  While you're at it, check that the Terminal labelled Track Power has continuity (low resistance) to the center rails.  Likewise between the GND terminal and the outside rails.

In testing, if any of the meter readings are a high Ohms value or OL, then there is a poor connection in the circuit between the probes.

Note: that there are two insulated outside rail sections adjacent to the divergent side of the frog which are intended to be electrically insulated from the other parts of the outside rails.  There is a small gap between these rails and the outermost ends of the outside rails on the divergent ends of the turnout.  These insulated rail sections are used to throw the switch when a train enters the switch set to the wrong direction in order to prevent derailment.  When these insulated rails sections are shorted to the opposite outside rail by the train wheels/axles, the internal circuitry senses this and changes the turnout's position to the appropriate orientation.

Soldering the folded rail tabs to these bus/jumpers/metal plates inside the switches (which are intended to pass current around the frog and the insulated rail sections to the otherwise physically separated rail sections at each end of of the turnout), may fix this issue.  Tightly crimping the rails around the track pins may also help.  Providing track power feeders to track sections close the the switch and to the Track Power terminal on the switch would also help reduce the total voltage drop at the turnout rails.

Thanks for all the tips.  I checked the wiring and it is correct from the factory, so that isn't the issue.  I also checked continuity with a meter, and that is good.  What is so strange to me is that there is no track power when running from Aux power, but when I insert the jumper track power is perfect.  I have tried swapping out switches, and I get the same error. 

Steve - If I understand what you are saying, track power to the switch always comes from the adjacent track sections no matter what?  Aux power only powers the lantern, controllers and switch mechanism?

@tumbleweed56 posted:

Thanks for all the tips.  I checked the wiring and it is correct from the factory, so that isn't the issue.  I also checked continuity with a meter, and that is good.  What is so strange to me is that there is no track power when running from Aux power, but when I insert the jumper track power is perfect.  I have tried swapping out switches, and I get the same error.

Steve - If I understand what you are saying, track power to the switch always comes from the adjacent track sections no matter what?  Aux power only powers the lantern, controllers and switch mechanism?

I'll start with some terminology.  On the Switch Terminal labels, Lionel refers to the "Power" and "Ground", which I prefer to call Hot and Common respectively.  With the jumper installed and everything working as it should, power (which is actually Hot and Common) comes into the switch via the center and outside rails.  Common (GND) is distributed from the outside rails to all "ground" parts of the switch including to the GND terminal; its all connected if there are no internal faults.  Likewise with the Hot (Trk Power), it comes into the switch via adjacent tracks' center rail and should connect internally to the "Trk Power" terminal (unless there is a fault).

Installing the Jumper between "Trk Power" and "Aux Power" is how the switch's internal electronics, etc. get their Hot with no dedicated Aux connection.  One can also provide Hot and Common track power feeders from the main Track power buses directly to the Trk Power and GND terminals to reduce voltage drop on the switch's rails.  BUT, one should also bolster the adjacent track connections (by adding feeders to those adjacent track sections) and check for poor conductivity (and correct this if applicable) through the adjacent track pins.

Providing details of exactly where your good continuity measurements were taken may reveal some electrical paths you may have overlooked.  When I check FasTrack Switches, I use my meter to trace every part of the electrical path making sure to follow the loop from beginning to end.  If your train is finding a lack of sufficient voltage, use that location as a guide for where to begin and follow that path all the way to the adjacent tracks' rails.  Remember to check both the Hot path (center rail) and the Common paths (both outside rails independently).

Just curious, What's on either end of the switch? Do you have an isolated center rail  with the jumper underneath removed on both ends?  That would prevent the center rail from getting power through the switch while using AUX power. Provide a picture before you do anything so we can see what you got going on.
Like Steve said above, use a meter and check each track joint. Your losing power somewhere in the track. Especially if you replaced the switch and still have the same issue.

Steve and Jayhawk - Thanks for the additional ideas for troubleshooting.  Independent of the switch issue, I have decided to replace an adjacent section of track (upgrading a curve from O-60 to O-72).  I need to pick up some track this weekend to do that, so I'll let you know my progress after I complete that change.  Thanks again!

FWIW, I found a number of Fastrack switches simply lacked continuity through the switches due to the lousy crimped contacts internally.  I cured a variety of issues with Fastrack switches by simply removing the back and soldering all the crimps.

I finally resolved this issue.  I upgraded a curve from O-60 to O-72 leading into the switch, and that resolved the issue.  I must have had a bad piece of track leading into the switch.  I had checked the old O-60 curve for continuity with a multi-meter, and it was all good but something was still wrong with section of track.  Thanks for all of the advice and help.