You should also measure the stall current of the loco motor before taking anything apart. This will let you know what amp rating the decoder needs to be, or if the motor needs to be replaced. Just put the current meter (Multimeter) in series with one wire of the DC test power pack and the track the loco is being tested on.
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.
Do not attempt this without a VOM. A meter will be needed at som e point to measure motor current, and electrical continuity.
Rich
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.
The shell is no problem. Neither is the motor frame unless one brush has been irreversibly grounded to it. The only things that absolutely, positively must be isolated are the motor brushes.
One brush is already isolated. Isolating the other might require breaking a solder joint or slipping a bit of insulating tubing (stripped from a wire) over the bare side of the wishbone spring on an open-frame motor.
For safety's sake, there should be a layer of insulation between the decoder and anything metal that could be connected to a rail. A strip of vinyl electrical tape is all that it takes.
Chuck (modleing Central Japan in September, 1964)
Jay
C-415 Build: https://imageshack.com/a/tShC/1
Other builds: https://imageshack.com/my/albums
Recently, at a local auction, my dad and i acquired several brass locomotives at dirt-cheap prices (mostly Overland, but some Pacific Pike), including several CN GP40-2W's and M420W's, a CN GP9RM, and a beautifully painted CN C44-9WL (it's worth near $1000, and it sold for $45). Unfortunately, it seems that a talented modeler passed away, and the family had no idea what his collection was worth. We did, and made off like bandits, as there was only one other serious bidder.
Anyway, it leaves us with a decent number of brass locomotives that will eventually be equipped with DCC decoders. A local hobby shop has a service that they will install the decoder for you, and i was discussing this with one of their employees. He said that the brass shell has to be isolated from the rest of the locomotive for dcc operation. It brought me to wonder: is this actually true, and if so, how is this done? Also, what other modifications must be done to a brass diesel for dcc operations?
Thanks,
Peter.