Or in cases like the Blueline AC6000 there is only one way that the NCE N14IP only fits one way, Backwards. It's how I learned about CV29 early.
Springfield PA
Sometimes it's just the decoder plugged in backwards. The function in CV29 was made just for that reason.
Playing around with CV29 is one way to do it, but ideally the loco should move forward in the forward position (an F should be stamped somewhere on the front side of the loco shell).
If it is running in reverse in the forward position, chances are the decoder is installed in reverse or the two direction wires are reversed on the decoder.
Rich
Alton Junction
Also make sure you know which end is the front!! It's easy for steam (well except for cab forwards) and F units, but with road switchers it can be a little tricky. For example, a manufacturer might decide the short end of say an GP-7 is the "front" and wire their lightboard that way, regardless of whether the body shell has the "F" on the short hood or the long hood. So it could be the engines are both going forward after all...
when in doubt, do a reset first and see if that fixes it. I have had that happen and doing a reset often times fixes it.. if not then go to CV29 and set the direction.
You can reprogram CV 29 to change the polarity of the motor outputs. But first were the locos programed to run in a consist, did you install the decoders your self, do the decoders have an 8 pin plug in harness [it could be reversed on one of the locos], or were they hard wired and the motor wires reversed, you can swap the wires over[ involves disassembly and soldering] Alot of scenarios here, we need more info on your part. Truck.
I have 2 locos on my dcc layout & they have opposite forward/reverse.
Can I reverse the polarity of the one that operates in reverse ? Or is there some other solution to this problem?