Walthers 0-8-0's a real problem!

[JGray]

I did a post about this yesterday and didn't get much of a response, so I'm trying again with new data. I'm building an N Scale layout. I have it to the point where the mainline is completed. I can now run engines. During the tedium of building benchwork, roadbed, laying track and wiring; I have been accumulating engines to keep me motivated. All of the engines I have purchased are new, nothing is used. I have two Model Power DC locos; a Mikado and a Pacific. I have three Walthers Proto 2000 locos; a DCC/Sound 2-8-8-2, and two DC 0-8-0's. I also recently acquired a Bachman DCC 2-6-6-2. Plans are to equip the DC locos with Digitrax decoders. My layout has a Digitrax Zephyr with one tethered UP-4 running through a UP-5 loconet outlet. I have a PSX-3 that currently is using only one breaker wired to the completed mainline. The mainline consists of eighty-seven feet of track. The buss is #14AWG with #20 feeders about every six feet using 3M suitcase connectors. All track is Peco code 55 with soldered joints. This weekend, I assembled locos and ran them to break them in. Everything was BEAUTIFUL. The two Model Power DC locos ran GREAT. There were a few minor track problems that were resolved with some filing and smooting out radii. Next came the Bachman DCC 2-6-6-2. WONDERFUL! It cruised like a big (N scale relative) cloud. Next came the two Walthers 0-8-0's. Both shorted out the track as soon as the power button was pushed. I moved on to the Walthers 2-8-8-2 DCC/Sound. Initially it moved a short distance then shorted the track. I found the problem and resolved it. It is now running like a dream and the sounds are awesome. I spent the entire day today trying to figure out the two 0-8-0's. I have checked tender pickups and they are OK and are not crossed. I checked the wheel sets to make sure none were uninsulated. I tried reversing the tender to engine plugs. I disconnected the engines from the tenders. The problem is in the tenders. They short the PSX-3 when power is applied. About every 2 seconds, the PSX-3 tries to reset and the tender backup light fires like a flashbulb, then it shorts again. My next plan is to remove the circuit boards from the tenders and see if I can find any wiring shorts there or in the 8-pin connectors. I purchased the two 0-8-0's a few months apart. All I have read about these engines are raves since they went to tender pickups. The odds that I got the only two defective ones with a few months between purchases is about those of winning the lottery. Has anyone experienced the problem I have described???? If so, please share with me how to resolve it. Thanks, Jim

[selector]

 I'd still bet someone goofed the assembly and installed a wheelset or more the wrong orientation.

But, if that is well and truly not so, then there is a stray wire or a bit of solder on the circuit board of the decoder where it shouldn't be.   It is a bridging problem.

Or, possibly stripped insulation letting a wire touch metal.

Or a decoder improperly connected.  One end of one wire, possibly both, is in the wrong place?

-Crandell

[JGray]

Thanks Crandell for the reply. Yeah, I have removed all the wheel sets from the tender trucks and checked them with an ohm-meter to make sure they are insulted. I have also checked that all the insulated wheels are on the same side, etc. Like I said, my next move is to look for some wiring defect that allows current to run to ground. It just seems improbable that I have bought two of the things a few months apart and scored 100 percent defective, when no one else seems to have had anything but good results with them. A bad wiring job due to a worker losing concentration because he was overcome with gratitude about being a part of Chairman Mao's celestial workers' paradise is understandable, but how did I wind up with both of them? I still am hoping that this is something that is fairly common among the Walthers 0-8-0's and that surely someone else has encountered and overcome the problem. I can struggle through tracing and spotting wiring defects. But, when it comes to the stuff on a circuit board, I'm lost. Jim

[locoi1sa]

   Jim

 The tender wheels should be front truck insulated on one side and the rear truck insulated on the other side. Not on the same side! Another thing could be that you do not have a decoder installed in the tender. Your circuit breaker could be seeing the non decodered loco as a short instead of a load.

     Pete

[JGray]

Hey Pete. Thanks for the reply. Having the insulated wheels on the same sides was one of the first things I noticed two days ago. I tried setting them up with the front truck wheels arranged one way and the rear truck wheels on the opposite side, but no luck. The 0-8-0 has a unique setup in that the pickups ride in a flange on the inside of the wheels. One wheel is insulated from the axel while the other isn't. Therefore, both sides pickup current independently and allow each truck to pickup from both rails. The pickups should be wired to accept the wheel arrangement. I figure there are a variety of wheel arrangements which could serve depending upon the wiring arrangements. Rather than guessing, testing and shorting, I will check that when I remove the circuit board. The decoder plugin has a circuit board plug installed in it. The meager instructions that come with the engine tell you to remove and discard this item when you install a decoder. I assume the plug provides a completed circuit to simulate the presence of a decoder during analog operation. This is another item I will look into when I remove the circuit board. I'm still amazed that two engines purchased months apart are doing this and no one else seems to have encountered the problem. Of course, I'm also amazed that this was not detected in the much acclaimed "factory testing" mentioned in the owners' manuals. I have sent an e-mail to Walthers customer service describing the problem and requesting help. If they come up with a resolution, I will let you know. Jim