The decoder is plugged into the end of the cable, which has a 9-pin JST socket on it, and then shoved back into the tender through the slot in the front.. Pull the wire and decoder out of the tender and make sure the decoder is plugged firmly into the socket.
If this is not the problem, then perhaps one or more wires has frayed where it goes into the back of the locomotive. Check the wires here to see if the insulation has rubbed off any of them.
If neither of these is the problem, then perhaps the electrical pickup from the locomotive wheels needs to be cleaned. The tender does not pick up power on these engines, only the locomotive wheels do. Bronze wipers rub on the insides of the drive wheels to pick up power. If the insides of the drivers are dirty, you lose electrical contact.
I have a 282 mikado that stops when you move the cable where the dcc is. Anyone else have this problem? I am a little scared to take anything apart. Any help? I see there is another post about these locos maybe they might know .Help please rambo1.....