Ok, after a few years here I've got something to pass on that, hopefully someone will find useful.
Turned on the layout a few weeks ago to find a major short in the accessory circuit popping the breaker on the z4000. Traced it to one of my Lionel lighted telephone poles, removed it from the layout and life was back to normal. Found it weird that it was shorting, but couldn't argue—back on the test bench showed the same result. At the same time, these are 30ga wires going to mini bulbs that draw way more power than leds, crammed into a very small space that could very well lead to problems. Put it up on the bench and contemplated my options: 1) trace that puppy and figure out how to open up the telephone pole itself and attempt a repair, or 2) send it Lionel (postage alone kinda ruled that out) and finally 3) just have an unlighted pole, which was a bummer, but the easiest route by far.
A search on the forum lead nowhere, most people seemed stymied by opening the pole up, and I was resigned to a sad dark spot on the layout when, (here's the blame part) Mike R. reminded us of the upcoming 50% sale. Nosing around the Lionel parts site, I found the replacement bulb/shade/wire assembly priced at 4 bucks Minus the 50% I had to give it a go. (Yes, I ordered other stuff, so shipping was amortized over the whole lot.)
Parts showed up yesterday, and after the usual replacing traction tires and crossing flashers the kids mowed down, it was time to start tracing the short. I thought I might find it at the base where the wires are shrink wrapped, but no luck, though there was thermal stress on the insulation of both positive and negative leads. Not really a fan of the wires acting as a fusible link, though the z4000 breaker did kick in and do it's job before something major happened. If anyone has suggestions for better protection on an accessory circuit , I'd love to hear.
Anyway, I decided to investigate opening the pole itself, applying debonder to the base, and up above where there was a clear connection by the cross supports. All that did was allow me to pull the top section off and gaze down into the pole with no obvious casting lines in sight. The base attempt went nowhere, it's seemingly molded as one piece. Strike two, as they say. This left me with no other option than to carefully remove the remaining shrink wrap and pull the entire assembly out from the pole, hoping I could thread the replacement unit down the interior, which I did. (Previously I had isolated the offending bulb assembly so I knew which to pull.) Threading the wires down into the pole was a bit tricky, but eventually worked. I think some kind of improvised snake would've helped, but it all worked out. Reglued the top section, mounted the shade support wires and the pole is back in action on the layout.
Final analysis regarding the short is that Lionel uses a solid copper wire as the gooseneck support, shrink wrapping it, along with the 30ga wires from the bulb. Cutting it to length, as with a standard pair of wire cutters leaves a sharp edge that, when shrink wrapped with two 30ga leads and then twisted into the telephone post yields ample opportunity for a nick in the thin insulation of one or both leads. Time and current draw did the rest. If an insulated piece of solid wire was used it may have helped, but hard to say for sure. I think Andre Garcia's method of using ca adhesive on shrink wrap tubing to form the gooseneck is a much better approach, though not sure how that would translate to a high volume production environment. The other option, which is surely coming, is to use mini leds, which draw so much less current that the chances of a short due to current draw melting insulation would be greatly reduced.
Personally, I like the mini bulbs—they have a warmth that leds, while getting better, lack. In a way, the mini bulbs also remind me of layouts past. I would never go back to the old, current sucking bulbs of yesteryear, but having a few sprinkled here and there garners visions of some kid in the 50's, transformer in hand watching that Western Pacific going round and round...
I suppose they just send you a new pole.
