Headlights come on for opposite direction?! Please Help ASAP

[liamneuser]

I just installed a DCC Decoder in my GP-38, that I took from another GP-38. It runs fine, and the headlights come on, but when I'm going forward, the back comes on, and when going backwards the front comes on! How do I stop this from happening and fix it to how it should be? Any help would be greatly appreciated!
Thanks, Liam

 

[rzw0wr]

I would think you have the motor leads reversed.
What decoder are you using?

 

[liamneuser]

I'm not sure the name, it's a Bachman decoder that came with a GP38. What exactly are motor leads? I've tried switching the wires to the motor from the DCC Decoder, but it just made the engine go backwards and the lights stay the same. It goes the right direction, but the lights go the wrong way.

 

[liamneuser]

It doesn't have white or yellow wires.

 

[Iron Horseman]

It doesn't have white or yellow wires.

How does the power get from the decoder to the lights?

 

[D&J RailRoad]

Lood at each of the lights, forward and reverse. You will see one wire that is the same color going to each light. This will be your common wire. Leave that one alone. The other wires going to the lights will have to be swapped.

 

[liamneuser]

I actually figured out a solution. I ran a wire from one end of the decoder to the other for the opposite light, and vice versa! But thanks for all the help!

 

[Mark R.]

If it has an 8-pin plug, you probably had the plug in backwards ....

Mark.

 

[dinwitty]

sometimes with the plug backwards it messes up some grounding or light connections and the lights never work right, thats often on engines with specialized circuit boards, you may be better to get the plug right, or your engine will run reverse to all other engines unless you reversed its wires. It will run...tho ...8-P