Rivarossi DCC

Dave         Try this web site http://www.tcsdcc you may find what your asking for there.     ron netti

Rivarossi loco power

Dave:

Rivarossi locos are kinda weird-- sometimes they pick up thru the tender & other models use pickup wipers on the back of the drivers. I'm curious as to how the motor was wired before you started installing the decoder. Chances are there is a wire going to a couple wipers on the insulated side & the other side drivers are "grounded" thru the frame. There is a lesson to be learned here: spend a few minutes making sure you know how the engine picks up power before you start wiring a decoder! On top of that, isolating the motor on some Rivarossi loco ain't easy, & usually it's easier to replace it with a small can motor. Their motors are pretty robust but have been known to spark a lot at the brushes, which will drive a decoder nuts. Good luck!              Bob Battles

Rivarossi loco power

Bob:

Thanks so much for your suggestions and it is truly my fault not have taken a few quick shots of the teardown for the Mikado. Live and learn. Anyway I'm thinking that just maybe the tender is the positive side pickup, there are two spring loaded pin shaped wipers on the left hand side of the loco connected to the frame... the lead and trailing drivers. So, I will cobble the thing together and test it on the main before I go any further. If that fails I might consider using it in the yard as a very worn and dirty unit waiting for limited shop services at TYE Washington (the area I am modeling).

Dave

I feel your pain

Similar problems about 12 months ago with a Riv Allegheny Tsunami install. Ended up (dangling participle alert) removing all factory wiring, installed new wire, new harness, and re-doing the pickups on both loco and tender.

Tender vs. engine pickup

Dave:

If the drawbar has a contact wire & the stud it mates with is insulated with a wire coming off of it, then yeah, the tender is picking up power from one rail. Usually the loco will have the pickup wipers on the back of two or three drivers plus sometimes the trailing truck, all of them wired to the insulated brush. If it does, then the tender is out of the picture & it picks up just thru the engine. I hope this helps narrow it down, cuz you don't want to play "guess the pickups" when you're wiring in a decoder!

Bob

That Rivarossi cussed engine

Bob:

Yes it does have a draw bar with a stiff spring wire coming off it.  Does it make any difference which way the tender trucks are put back? Are they pickup one side only? and, how do you tell which side is the "right" side? I must really sound like a dork for getting myself into this situation... if I had taken more care and shot some photo as I disassembled the Mikado.

​Thanks so much for you comments, I may make it yet...

Dave Parson

Rivarossi tender trucks

Dave:

It sure does make a difference which way the tender trucks are in, but it's easy to figure out which way they go: they'll be picking up power on the side opposite the engine. So if the loco has the Right-Hand (facing forward) drivers making contact with the frame, then the tender trucks will have the wheels on the LH side making contact with the tender frame & then the drawbar; they will then be wired to the insulated motor brush. You'll need a good ohmmeter here, one you can zero with the leads touched together. But after you figure all this out, be sure to isolate the insulated motor brush before you wire up your decoder or bad things will happen when you power it up! I wrote an article on installing decoders in HO steam power in the Dec. 2013 issue of MRH which spells this out so it may be worth reading. Good luck!       Bob Battles

Invest in a cheap digital meter!!

Dave,

Buy yourself a cheap digital meter. Harbor Freight Tools has them at a regularly at $9.95 and on special $2 or $3.

Stick it on ohms and measure from one side of loco to the opposite side of tender if you get an open circuit (usually displayed as O/L) then do the same thing from the opposite loco wheels if still reading open circuit check from loco drivers to tender wheels on the SAME side, if you get a short circuit your tender trucks are on backwards!!

If you read a low resistance then less than 100 ohms but not zero (or less than about 5 ohms) then all is OK if the resistance is less than 5 ohms you have a short circuit somewhere in the loco!!

Remember to check ALL tender wheels as it is possible to get some one way and some the other causing a dead short.

Don't be afraid of meters they are easy to use and extremely useful for model trains.

Check this link for simple instructions:-

http://www.trainelectronics.com/Meter_Workshop/