You really shouldn't run a decodered loco with a power pack .. unless you want to replace the decoder .. it's looking for a constant voltage ..
http://www.hollywoodfoundry.com/Docs/DCC%20Explained%20Simply%20Part%201.pdfQ. Can I run a DCC equipped locomotive on a plain DC system?
Again yes. But in this case the decoder equipped model will require a higher starting voltage before it begins
to move compared to other models on the track. This is because a good model motor may begin to creep
along at around 2 volts, but the decoder in the DCC model requires a higher voltage to operate the electronic
decoder chip and will not start to move until there is enough voltage on the track to start the chip running.
If you want to run a DCC equipped locomotive on a plain DC system permanently, my recommendation is to
remove the decoder if possible. If it is a plug-in decoder, this should be relatively easy to do, providing you
insert a blanking plug into the vacant decoder socket.
Another problem is with pulse-width control DC controllers. The DCC locomotive will see the pulses as
potential control pulses and may behave erratically. So no DCC locomotives on pulse-power controllers.
And another potential problem is with feedback DC controllers, again the DCC equipped locomotive may
behave erratically.
General Rule: Run DCC equipped locos. on DCC systems. Run DC locos. on DC systems. Do not try to mix