Which power wires do I use on an LGB F-7 Trucks

[trainman605]

I'm going to install Rail Pro in an LGB F-7, which color wires on the power block do I use. I have done this before on my LGB Rio Grande diesel, I'm thinking I used the Brown and Yellow wires, is that correct or not. I think the Red wire is not used, but what is the Red wire used for. Please correct me on this, I could dissemble my LGB diesel to see what I did but would rather not do that just to look inside. Thanks for your help, trainman605

[gregeusa]

Do your trucks have 3 wires or 4 wires?

Are you running from track or battery?

I can give you the answer if you answer these 2 questions.