P2K gp-9 wrong direction


C

cfinchum

Member
Hey guys. I converted a p2k gp-9 to dcc. I installed a digitrax dh-123. now the loco goes backward when forward direction is selected on the dt-400. I doubled checked wiring, orange wire to top of motor, gray to bottom. both trucks to red wire and black to ground. Tried changing cv-29 to 7. When that is entered the loco does nothing,:confused: does not even power up. Then I reset cv-8 to 8. I reprogram loco number in and loco goes backward when forward is selected again. I'm I missing something, I just can't figure this out. Can someone help:)CF
 
If you were running DC I would say the trucks are in backwards/reversed. W/DCC that might not be the problem.
 
Thanks. The lights are not hooked up, But Larry you may have the answer. because I tried it with a dummy plug on dc and it did the same thing. I'll try reversing the trucks. Rats, I was really proud of myself because I did a nice and tidy install on this one, o'well,, live and learn. CF
 
When you take it apart, just reverse the leads off of the decoder to the motor. If you have the orange lead on the top of the motor, put the grey one there instead, place the orange on the bottom. This will change the direction. You can also do this by changing some CV's with the throttle. But I have not used my throttle to program with, since I download JMRI, and attached it to my program track.
 
Well, Tried reversing trucks. Put engine back on track and it sent a short to layout. Have now taken it apart. Tried a new harness and put orange wire to top of motor and gray to bottom. Hooked the black to the frame. Now no power to motor. have motor out of frame and still the motor does not spin. Tried reversing wires and still motor does not spin. Larry, could I have toasted motor? I tried this with a dummy plug to try dc. CF
 
Digitrax. Just trying to figure out why motor does not want to spin now with power put to it. When the first time I converted it I used a dummy plug to test it. ran fine. always something.CF
 
The GP9 uses the frame and weight for power pickup.

I don't get why you changed CV 29 to 7... Are you using a 4 digit (128 and up) address? If so, changing it to 7 would not work as 7 is the value you would use if you only had a 2-digit address. If I were you, I'd try reading back CV 29 and adding 1 to it to change the direction. If using a 4-digit address, you'll probably use a value of 39 for CV 29
 
I wished you had answered the first time I posted. The only thing I could fine in the wonderful digitrax manual about reversing direction was changing cv-29 to 6 or 7. When that didn't work I just reset it back to factory. Now I just need to trouble shoot why the motor won't spin and start over. So now I know to change cv-29 to a value of 39. Thanks. CF
 
FYI, changing the trucks is the DCC equivalent to picking up the loco and turning it around, basically on DCC it won't do anything. Things that would make it run backward could be the orange and gray wires being reversed or the motor being turned around, front of the motor toward the rear of the loco. Another possibility is if the motor was disassembled it was put back together wrong. As far as it not running did you remove the clips that hold the spring and brush to solder the wire to them? Did the spring go missing?
 
Assuming that the brush springs didn't fly off into the hinder land, here's a quick test.
Remove the dummy plug, and run DC leads directly to the motor. If it runs, then something is amiss with the wiring, or the dummy plug isn't doing what it is supposed to do. If it doesn't run then something's amiss with the motor.
 
Got the motor to spin. Did not have a good ground. Going to rebuild loco today and see what happens. If football doesn't get in the way.CF
 
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