One more thing I was going to add, where did you make the neg.(-) black wire connection? One of the best ways is to drill and tap a hole for a 2-56 screw in the frame, and attach the black wire to that.
Mike
My You Tube
Thanks guys for the responses and good things to look for and check. Will let you know the results soon. JRP
And, check where the frame and trucks meet. Both sides have to be clean, free of any paint and oil, as that's where the (-) (black) connection is made.
As long as the pin on the cross member of the frame, and the hole in the truck, fit and make contact, and the truck has the normal amount of room to swing side to side, you should be OK with using F7/GP7 trucks.
Also make sure the little brass "bearing" blocks, that are on the axles, and contact the metal strip on each side of the frame, are clean, free of any oil, etc. Those actually where the track power is picked up by the trucks.
Mike.
Athearn F7, GP9, GP35 and GP38, power truck set, front and rear. #42011
Power truck front. #42010
Power truck rear. #42020
The truck upright clips as you say, should be on the same side of the loco.
Remember those two little barb tabs on the contact strip on the bottom of the motor that hold the brush in, bend them flat in to the motor and you need to solder a wire (orange or gray) to that clip when it is remover from the motor or you could heat the strip and kill the brush spring that powers that side of the motor. Tape on the bottom side of the motor to insulate it. Watch that the brush and spring doesen't pop out of the motor when you remove that clip to solder a wire to it.
I added a can motor to an older Athearn GP7 dummy, using new Athearn trucks (plastic push-in sideframes), and while not DCC, it's hardwired from the trucks to the motor, with all of those contact strips removed or at least cut-down. It runs great. Keep in mind that the trucks are not alike - you need a front truck and a rear truck - different part numbers. Also remember when installing the decoder that each truck picks up from both rails, so one wire from the same point on each truck to the same connection point on the decoder, and one from each of the other similar connection points to the other appropriate terminal on the decoder.
Also, remember that one of the motor contacts is partially hidden, located at the bottom of the motor. I don't use DCC, so these suggestions may seem obvious to you, but hopefully are of some use.
Wayne
Happy New Year all,
I am in the process of adding a new Athearn r-t-r BB motor, new decoder (Eco200), and new power trucks and wheels to an older blue box "dummy" GP38. For some reason, I can't get any power up once I have all the wires soldered (front p/u red to clips, left p/u black to body, orange and gray to motor). The motor is safely insulated from the frame and so is the decoder. I'm using Athearn power truck sets, 4 axle (#ATH42011) made for the F7/GP7, but do not think that using them on a GP38 frame would make any difference as they seem to fit. I use JMRI to test and program. Any suggestions? Thanks for reading.
JRP