Difficulty Trading Tenders on Bachmann Niagara - Help!?

[Chaparral66]

Hello, I have a new Bachmann Niagara (nice loco!) whose tender will not run on my layout due to its wheel arrangement.  I cannot modify the trackwork on the layout to accommodate it.  Instead I want to swap this (impossible) tender for a shorter one with normal trucks.  I purchased one on-line, Bachmann item number 89832, which Bachmann tells me is at least five years old and whose wiring is both unknown and incompatible with the Niagara.  When I plugged the replacement tender into the Niagara, incidentally, it ran perfectly but only backwards!  Also, the light on the loco did not light up.  I offer this info as clues.  Can anyone help me make this conversion or recommend a model train electronics shop that could do it. I am wondering whether the problem is that the wires in the harness from the replacement tender are attached to the four wire plug in a different order than they are in the harness from the Niagara's original tender.  Maybe it is that simple?  In any event, this is a bit over my head.  Any suggestions?  I am in Buffalo, NY, by the way.

[jonathan]

Does the replacement tender have a DCC Decoder in it?  One symptom of a backwards installed decoder is the locomotive will run, but the lights won't work.

The simplest solution is to remove the electronics from the original tender, and put them into the new tender.

Many posts about this in the past.

I have done the electronics switcheroo many times in the past.  Always works for me.

Regards,

Jonathan