Need help restoring a RR Crossing light and bell

How'd I miss this posting?  Sorry to not get back to you much sooner.

From the looks of the cables you have connected, I'd say you are possibly using a battery "trickle charger" ???  Those are usually good for 4 to 8 Amps, so I'd assume you have enough power to operate the bell.

A possible cause (other than a power supply that is not capable of providing the power) would be that there is an open circuit somewhere.  Some quick checks can be attempted with just the power supply you have.  Just be careful to not short the power wires to each other... that includes touching the big aligator clips to each other... AND... touching them both to something that has very low resistance (no "load" to limit the current flow); such as having one connected to one of the binding posts and then touching the other one to the other end of a wire directly off of that binding post.  If you are using a car battery as the power source, it is capable of dumping several hundred amps and the sudden rush of current can weld the aligator clamps to each other or what they are touching... amidst lots of sparks and flying molten metal.  If you are using a trickle charger, you could still get some major sparking so be careful where you go poking around.

Sorry to be so safety minded, but I worry about offering advice to others without at least some 'scare tactics' to TRY to keep people safe.

Ideally now you would have an Ohmmeter, Voltmeter, or some other circuit tester to test that there is not a lose connection or a burnt out component.  It is possible that the unit is broken and that is why it was sold to you.

Primary components to check would be the switch that breaks the current flow when the coil pulls the armature down to ring the bell and the coil itself.  Bells usually work by energizing a coil to make a strong magnetic field which attracts a metal object (the armature) that in turn pulls something against the gong to ring it, but at the same time, that moving metal pulls a mechanical switch that breaks the circuit so the coil loses power and the magnetic field goes away and releases the metal and a spring (or gravity) moves it back to the starting position, which allows the mechanical switch to make contact again to re-energize the coil to again pull the metal part back... this repeats as long as the external power is supplied.

If the coil is bad (broken wire internally) then no current will flow, thus no magnetic field and the bell doesn't work.  If the switch is bad, then the same thing... no worky.

Not much you can do if the coil is broken internally.  Maybe (really MAYBE) you could unwind the miles of wire inside it and find the break, repair it and then wind the wire back. (ha ha ha... not worthwhile to try, even if you could do it neatly)  Replacing the coil with a good one is the only "good" fix if it is bad.

If the switch is bad, it is possible that you could fix it, if it is just maybe bent to the point where it won't make contact when the armature is in the relaxed state, you might be able to adjust the bend to put it back in contact.  It is also possible that the contacts are just very dirty and a good cleaning will fix it.

I think the first thing I would try is to connect the power source as you have it, and then with a stick (pencil, etc.) push on that curved piece of metal that constitutes one of the contacts of the switch to make sure it is in contact with the other contact on the armature.

The switch is shown in the bottom photo of your Nov. 20 10:20 AM posting in the upper center.  That long thin curved strip bent over the bronze piece that has the white and black wires connected to it.

It should, with the armature in the relaxed state, be in contact with the reversed 'L' shape metal contact on the black armature.

The armature should be free to move up and down, too.

There are other things that might be repairable, such as the resistor being bad, or a loose or corroded connection someplace (but it looks fairly clean inside so is probably not a problem)  Let's see if it is the switch first since it is the most probable problem and the easiest to test by just pressing on it.  There are other things to try, but that is the simplest and quickest.

You might need to clean the contacts.  Get a fingernail emery board and lightly  "sand" the surfaces where the curved strip contacts the "L".