151 semaphore

[srguy]

Bob:

Sometimes a simple bulb swap is the answer. Just switched bulbs from the O22 to the 151 and vice versa.

Thanks for the suggestion ... Jim

[Dave632]

 The fabric covered wire is the + lead.

Start at the bulb socket ground and go to the 151 base where the ground screw is connected and see if there is continuity between those 2 places, then work your way toward the socket, checking the ground along the way.

[srguy]

I''m using LED bulbs (runs cool where incandescents run far too hot). I did try the bulb I was using in the semaphore in an O22 switch and got full power. I'll try different bulb in the semaphore and see if that works. Sometimes the simplest resolution is overlooked. Thanks

[lionelsoni]

You tried the old lamp in a new socket.  Have you tried a new lamp in the old socket?  Lamps can light even with a broken filament, if the filament happens to hang where it can make contact, misleading you to think that your old lamp is okay if it lights in another accessory.  And the solder bump at the center of the end of the lamp base can become squashed to where it might not make contact in one socket but will in another.

[srguy]

The lamp housing screw is secure. If the bulb socket is not properly grounded, where do I look for an interuption? The base of the semaphore has a plate that look impossible to remove and all the wires seem to be connected properly. There is one wire with a fabric covering ... is that the ground?

[RedfireS197]

The lamp housing is held to the signal head with a 2-56 machine screw.  Make sure it isn't loose.

[Dave632]

 I would take an ohm meter and check the continuity of the bulb socket ground to your transformer ground and then work my way back to the bulb socket if the meter shows an open circuit.

There can only be 2 reasons the light does not work. Either the bulb is not getting power, which can be checked right at the bulb socket or the ground is not proper. In most cases the ground is at fault. I think I had a similar problem with mine but I can't remember what I did to repair it.

[srguy]

If there was a problem with the ground , wouldn't there also be a problem with the operation of the smeaphore? Howw can I test the ground?

[Dave632]

 Most likely a bad ground. That is where I would look first.

[srguy]

Just noticed that the light went out in my 151 .... the bulb is good  ... checked it in another accessory. All the wiring appears to be sound .... the operation is fine .... any ideas on why the bulb won't light?  BTW ... I've seen the bulb light once or twice for a few seconds then go off. Appears to be a loose connection but what I checked looks good. Any ideas??