Porter 0-4-0

[ibglant]

I have a Spectrum 0-4-0 that has a problem.  With the direction switch in the smoke box to the right the engine runs forward but can't be made to run backwards.  With the switch to the left the engine will only run backwards, not forwards.  The engine is new.  My power pack runs other engines perfectly.  What gives with this 0-4-0?  How can I fix it?

[Jose Morais]

It seems to me that your Porter is OK and you have a problem with your controller. The Direction switch only changes the polarity to the motor, between Large Scale (LGB) and NMRA standards. In NMRA standards, the locomotive shall move forward with positive on the right rail, and the reverse occurs with LGB standards. So, according to your description, when the locomotive moves, you shall have (-) on the right rail and (+) on the left rail, so that the locomotive moves forward when the switch is to the right (Large Scale) and backwards on it is to the left (NMRA).

So, it looks as the wheel pickups, direction switch and motor connections are all OK.

It seems that the controller direction switch has a contact problem and cannot change the polarity to the rails. You can check this with a multimeter or by placing another loco on the rails.

Jose

[NarrowMinded]

What controller are you using?

Have you checked the power to make sure the output to the track is DC.

since your using the switch for direction assume there is no DCC involved.

NM-Jeff

[jpipkin]

If your other locomotives run correctly you have an internal problem with your Porter not your controller.   Contact Bachmann service or return it to where you bought it. 

Jim

[NarrowMinded]

jpipkin,

This is not always the case, he has not mentioned what his other locos are nor the controller,  he could be running  Markins with AC which would cause the issue he is having.

NM-Jeff

[jpipkin]

Excellent point indeed! 

[Joe Satnik]

Dear All,

If you asked me to build a DC loco that would act as ibglant describes, 

I would put a diode between a wheel pick-up bus and the NMRA/LS switch. {  ->l- = diode }

Right wheel pickups ---------------------->l----------NMRA-----------------------Motor +
                                                                             /LS
Left wheel pickups-------------------------------------Switch----------------------Motor -

This would allow only one direction running at a time, dependent on which way the NMRA/LS switch is thrown.   

http://www.bachmanntrains.com/home-usa/dwg/dwgs/G825X.pdf 

(Scroll to the bottom 2 pages, DC and DCC installation wiring diagrams)

My simplified interpretation of the drawings:

Wheel Pickups(L,R)-------------PC board---------NMRA/LS  switch-------PC board ----------Motor(+,-).

I would guess that the "DCC ready" PC board is mis-wired, shorted, or mis-jumpered for DC.

Strange, but not impossible: 

Is a diode being used as a jumper wire? 

Is the PC board mis-jumpered in a way that places the front headlight LED (which is a diode) between a wheel pickup bus and the NMRA/LS switch? 

Hope this helps.

Sincerely,

Joe Satnik