022 diagnosis—another one

[stuartmit]

Have seen a lot questions about diagnosing 022 failures, and now I have one which is electrical in nature.

here are the facts of my situation.

The unit is hooked up on constant voltage. The light is not lighting, but the bulb is tight and functional And as you will see, does light in some unusual circumstances.

 

the switch operates from the controller to either position, straight or curved almost all the time. Very occasionally, I have to operate the switch by rotating the lantern. And then it will work from the controller again. Perhaps there is a spot of corrosion on one of the contacts somewhere. But this seems to be a side issue, I believe.

The non-Derail feature is functional to pull the switch to the curve positoon but not to the straight position.

If the switch is in one position, and I connect the center terminal of the switch to an outer terminal, The light bulb lights but the switch does not operate. If I connect the other outer terminal to the center post, the light does not light and the switch still does not operate.

 

If I manually move the switch to the opposite position, I get the exact reverse behavior; the pairing of center post and outer which previously lit the bulb does not any longer, and the pairing of center post and other outer post which did not previously light the bulb does now cause the bulb to light. But in no case does connecting the center post directly to either outer post cause the motor to operate. 

First off, I can't understand why connecting the center post to outer posts does not cause the motor to operate because that is merely a parallel circuit to operating with the controller. Further, I also do not understand why the bulb is not lit unless I make the direct connection of the center post to one or the other of the outer posts. And lastly I don't understand why the  nonderail connection to pull the switch from curve to straight is failing to operate. In someway there is an open circuit between the straight control rail and the solenoid. can that be the explanation for all? If the conductor underneath were to be disconnected, would that explain the other failures of normal operational behavior? It's a real pain in the neck to get this thing out of the layout, and I believe it was working a week ago or four weeks ago.

 

additional crazy info
With the switch in the curve position, if I take a piece of wire and Connect the non-control rail to the binding post, the switch flips to the straight position. However if I place a truck on the switch so that it bridges the two rails, and then touch the piece of wire to the control rail and the binding post, nothing at all happens. It is if the electricity through the control rail is "finding" a circuit to "somewhere else" with a lower impedance than would be available through the solenoid, and so the electricity's path does not go through the solenoid, and the switch does not pull from curved to straight.

[stuartmit]

One other comment, cannot remember if this unit has the base plate, and if so if it has the insulating paper in it. But it might be bare  underneath to the plywood.

[stuartmit]

Just got a little more info.

when bulb lights as I described above it is not as bright as the bulbs in other units.

but  If I remove the switchcover had previously omitted underneath cover screws) and touched a wire to top of inside housing over solenoids and to third rail at full brightness. 

[stuartmit]

I have swapped other based with my motor, but symptoms stay the same

 

here is a néw thought:

It seems the possibility of a lower impedance path is two fold:

if the problem is on the motor unit, then if I reverse the motor position then the non performance woukd transfer to the other control rail non derail circuit--is that correct?

 

if the problem is on the base,  then the failure would remain linked to the straight control rail. 

so I will reverse motor position and see what happens, but regardles, I do not see any connectoons obviously disconnecTed. Not sure I know what to look for 

[BigAl 956]

I believe you have a few problems. First, how are you furnishing power to the switch? what is the power plug connected to and is it common grounded to track power? What voltage is your power set at? Second, sounds like you have an open in the non derail circuit. Take the bottom off the switch. I think you will find one of the non derail strips has come loose from the appropriate rail. Finally, Check the adjustment of the contact wipers internally in the switch motors. They get dirty and lose contact over time. They are also a bear to adjust.

[stuartmit]

tHANKS FOR YR EXCELLENT REPLY. I have found the problem this am; I had an open circuit as you said. I beleve the connection of the conductor strip to the control rail was faulty,  but for me, the simplest solution was to solder an 18 or 20ga wire to the control rail itself,and route it to the appropriate binding post.  I know that;'s probably not the best, but i'm not worrying about resale value on the swithch, and ballast will cover the wire.  

 

For the record the power source is low cvoltage throttle of an SW.

If the wipers had been at fault, wouldnt they have affected operation from the switch control box?

[stuartmit]

 By the way, there is an excellent article in classic toy trains February 2013 on tuning up of 22 switches with terrific pictures. That still doesn't mean that I had the skills to repair The conductor strips and wipers which constitute the path to the solenoid. My repair took less time and suits me fine!