Rivarossi 4-6-6-4 Electrical Mystery

Help! I have a Rivarossi Challenger, about a year old that is giving me fits when going around corners in a clockwise direction. Counter-clockwise is just fine on 22, 18 or 15" radius.
When going clockwise, engine will stall and cause short to DCC Command 2000 control, usually just as it is straightening out on any size radius. I do have a decoder installed in the tender and have rewired it twice to make sure there were no shorted wires. The engine will do this with the decoder out of the tender and the tender removed. I have isolated the can motor with liquid electrical tape and run without boiler to try to see anything that could short, to no avail.
Anybody out there have any ideas?

look for clips on the track some fall of the cars

I too had electrical problems with the Challenger after 16-18 months. IMO there are only two qualified master
steam techs.
One of them is Nigel, a member of this forum and a Riv owner. I’m sure that eventually he will see your help post and respond. Be patient.

Ray, Not being familiar with the Rivarossi brand challenger, but being familiar with the way a challenger operates, I would be looking closely at the front engine, since it is the one that does the pivoting when entering curves. Something in that front engine is creating your short when it pivots to the the right of center. I would also suspect, but not entirely positvie that maybe your track radius is too small for that challenger, since you mentioned 22, 18, and 15 inch radius curves. But like Chuck advised, Nigel is well qualified to help you here. Regards, Ken

http://www.trains.com/community/forum/topic.asp?TOPIC_ID=12850
maybe you could get some info from the posts in this topic
you did not state wich direction your Challenger was traveling frontwards or backwards
I once had a Rivarossi Challenger driving problem: driving backwards went OK, but driving frontwards It stalled after about 3 feet driving, the rods could not move anymore, shoving a bit: backwards it started again, then frontwards it stalled at the same place, diving rods completely stuck thought of an electrical problem, but when I picked it up a drive wheel fell off, just dangeling from the rods. I guess a miss alignment in the wheel setup, Have not had time to sort it out, also not enough knowledge, so that one is on display now.

This is a mystery.

Let’s try to isolate the cause, run the locomotive until it shorts out, turn off the power and disconnect the system from the track, then get out your multimeter. Verify there still is a short. Now drag the locomotive a 1/4" forward, remeasure, then back to its orginal position, remeasure, then back a 1/4" and repeat. If the short remains through this process, there is a good change to find it. Now take the locomotive off the track, put it on a soft surface up side down. Move the engines to the same position they were in when the short occurred. Use your multimeter to see if you can cause the short. Then move each piece a tiny bit to see if you cn eliminate the short…now it should be pretty obvious to see.

Thanks for all the help, will try your idea Nigel, hopefully I can get this figured out.

Ray

I have three Challengers by Rivarossi. The problem may not be a short at all. The engine may be loo=sing electrical pickup. I had the very same problem. The front set of drivers transfers current through the shaft through the pinion gear that contacts the worm gear on the motor. If there is too much lubrication in this area, the loco will stop when entering a curve. Also, the motor may not be exactly centered within its little cavity. Make sure the metal contacts the mate with the brush holders on your motor are properly seated. The rear drivers have a wire connected to them at the bottom. Both sets of drivers pivot on this loco. Insure that the wire is not broken. Good luck… Dave