Excuse me for asking before I even disassemble the thing, but I had a moment a the keyboard now.
I have a Bachmann decapod which suddenly developed a shorting problem (very, very few "miles" on this one too). The decoder install is good, The tender and decoder are fine on the track, but the loco itself shorts the layout, shows a short with a meter on the drivers, and does not register on the test track.
Could be a simple problem....maybe picked up some debris?
I have done over a hundred DCC installs and I run many locos but can't remember when I last has this problem so it never hurts to ask on this forum. The loco itself was never opened up for any of the DCC install so pinched wires, messed-up wipers etc. and so forth might be an issue only from the original maker, I suppose.)
Any hints on what to look for on this loco?
I am guessing that this loco has DCC installed. Is there a plug between the loco and the tender? For testing I would disconnect the decoder- Check with a OHM meter, the wheels of the loco to the frame on both sides( left rail- right rail).
A short is usually the hardest problem to find. You need to troubleshoot it in steps. Turn it over and look and see if anything has been picked up or is stuck in the running gear somewhere. Do a good visual inspection all over. If the tender trucks are used as pick-ups for power, make sure one of them hasn't gotten turned around. Next, take the shell / body off first, then test it again. While it is on the track and powered, move some of the wires around using a toothpick or other nonmetallic instrument, and keep an eye on the circuit breaker of whatever trip device you have to see if the power comes back on. The most common thing would be some wire that got mashed and is making contact with a piece of metal that is connected to the track electrically. Maybe one of the wheel wipers slipped out of alignment.As for what the actual cause may be, I wouldn't even begin to try and list them because there are too many possibilities. It may be that you will just have to keep taking it apart until you find something.If it is a new locomotive, send it back for repair. If it was a DC loco that someone else put a decoder in, you are either going to have to figure it out or see if you can talk them into fixing it.
Hope this helps some.
Elmer.
The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.
(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.
Cisco.
Since you have already tested the loco alone I would look at the drivers and side rods. I am not sure if Bachmann uses a half axle or if it has a thin insulating film between the tire and spoke hub. Also check the wheel pickups for one being bent out of place. Recently one of my brass locos rubbed the coating off a brake shoe on the wheel flange and started shorting. The only way I found it easily like I did was I saw the little spark before the system shut down. I doubt if your dec has metal brake shoes. There is something bridging an insulated gap that needs to be found.
Good luck and let us know if you have found it.
Pete
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
My guess is that one of the tender trucks got turned around, but knowing which one is going to require looking at the exploded diagram of the locomotive to see if it shows on which side the insulated wheels are supposed to go.
One way to somewhat isolate the problem is to disconnect the plugs between the locomotive and tender and then place them on the track one at a time to determine for sure whether the short is in the locomotive or the tender.
If neither one shows a short until the plugs are connected, then the most likely cause is a backwards tender truck.
The small, 2-wire plug feeds power from the locomotive's drive wheels to the tender and decoder. The 4-wire plug is the power feed from the tender to the motor and headlight.
On one of my Decapods, the mysterious every now and again, never concistant, pain in the but SHORT. turned out to be the motor itself.
Truck.
Thanks for the replies, guys.
The tender is the first thing I looked at....and as I indicated in my first post " The tender and decoder are fine on the track,
Going to figure it out tomorrow. My guess is, yes, it is probably the motor.
Cisco Kid Thanks for the replies, guys. The tender is the first thing I looked at....and as I indicated in my first post " The tender and decoder are fine on the track, Going to figure it out tomorrow. My guess is, yes, it is probably the motor.
This is all very curious. Manufacturer installed decoder, never messed with, tender trucks are oriented correctly, loco initially ran fine, now shorts the layout. What the heck?
Does it short on a particular spot or on a specific section of the layout? Only on turnouts? Sporadic shorting?
Tell us more.
Rich
Alton Junction
Carefully check the wipers on the drivers. Those are known issue.
http://members.shaw.ca/the.trainman/LV_Workshop/pesky-pickups/
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
If it's under warranty, it may be good to send it back as Bachmann may have developed a fix for the problem
Richard