You can just plug in in this case. What needs to be isolated are the motor brushes from the track pickups. In this loco the isolation is on the DC circuit board, when you remove the dummy plug from the DCC connector. There should be both an 8 pin and a 9 pin plug on this loco, the 9 pin one will be currently holding the dummy connector which ties the appropriate wires together so it can run on DC.
DCC Ready is really rather meaningless, there is no industry standard. Many times it means yes, a decoder will just plug right in. But not always. Sometimes modifications are needed. Athearn RTR locos are indeed DCC ready and a decoder can just plug in.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
The only instructions I have ever seen are to "Isolate the motor”.
From all the I have seen, when a loco says DCC ready, the motor has been isolated. There might be no connector in some locos and you have to solder wires to the PC board.
Just plug the decoder into the 9 pin connector.
I have not seen the inside but I understand the Athearn uses the Quick Plug which is 9 pin.
Cut back the shrink on the decoder just enough to unplug the connector with wires on it and plug in the decoder. Standard procedure. Many have done exactly that and SoundTraxx says it is OK. Pry the connector apart very carefully. I use a small jewelers screwdriver.
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.
Athearn seems to put both kinds fo connections in their locos, I guess so if you have a decoder that has an 8 pin plug hard wired to it you cna just plug that in instead of getting a new one with the 9 pin connector. That's how Ulrich made their upgrade lighting kit for the Turbine be plug and play - the decoder itself plugs into the 9 pin, but then their lighting bits plug into the 8 pin. Pretty nifty actually.
rrinker Athearn RTR locos are indeed DCC ready and a decoder can just plug in.
Not all of them. I have a pair of RTR GP38-2's and a pair of RTR GP40-2's that are not DCC ready.
The best I can tell is that the Athearn RTR's using the old Blue Box shells are not DCC ready, and the ones using RPP shells are DCC ready.
However, since this is nothing more than an observation on my part there may be exceptions, and of course it will probably change as the old Blue Box shells are phased out, re-tooled, etc.
But in either case, the RTR GP35's do use an RPP shell and as the OP stated they are DCC ready (I have three of those GP35's, also.)
If you've plugged the decoder into the 9 pin plug - you're all set. No more wires to do anything with, unless you disconnected them from where they were on the DC light board. You only need hook up the speaker and mount it in an enclosure and fit it in the shell somewhere. Without the speaker you should be able to run the loco, just no sounds. Don't let any loose wires flap around when test runnign it, if the speaker wire shorts to the rail you'll have a permanently silent decoder.