Trouble with my third sound decoder install.

[trainstrainstrains]

Everything works but the loco does not move.
It appears to be the loco motor. I checked the volts with a Multi Mater with the loco on the track and as the chuff rate increases in speed the voltage delivered to the motor increases also, but it does not move.
It is my Fleischmann P8 N scale, I have had plenty of trouble with this motor in the past but I worked on it extensively and replaced the carbon brushes and before the install it was working very well on DC. I disconnected and discarded the little electrical component between the two motor poles as one is always instructed to do when doing this type of conversion.  I have disconnected the motor from the decoder and applied direct voltage, even without the little electrical component between the two motor poles  it works fine. Back on the main track with the decoder it does not move at all, the voltmeter still reads from 0 to 6.5 volts and all else works. ?? 

[rogertra]

Everything works but the loco does not move.
It appears to be the loco motor. I checked the volts with a Multi Mater with the loco on the track and as the chuff rate increases in speed the voltage delivered to the motor increases also, but it does not move.
It is my Fleischmann P8 N scale, I have had plenty of trouble with this motor in the past but I worked on it extensively and replaced the carbon brushes and before the install it was working very well on DC. I disconnected and discarded the little electrical component between the two motor poles as one is always instructed to do when doing this type of conversion. But I wonder if this could be part of the problem. I am tempted to disconnect it from the decoder an apply voltage directly as I did before but now that the little electrical components are gone I don't know if I should. Should I? What else can I try?

I had the same issue with a 2-10-0.  There was a wire, black one IIRC, that had pulled away from its connection inside the loco's body where it wasn't visible.  It was, I guess, one of the wires for the motor power.

Cheers


Roger T.

[trainstrainstrains]

The motor works, so there must be something wrong with the decoder ot the install .

[trainstrainstrains]

Bad connection indeed, in my two other installs I simply disconnected and discarded the electrical components between the power wires to the motor and soldiered the wires to the decoder in the same place the wires between motor and wheel pickups had been. I did the same with this one.
Thete is a clip-on board where the wires are attached and that also holds the carbon brushes in place,  the power connection to the right of the motor is from a contact near the middle of the this clip-on board, on it's under side where it is not visible, not from where the + wire was originally attached on the top of the board.
By removing the electrical components I cut the connection to the motor. I have now connected the center and right soldier spots on the board and the problem is now solved.