My instructions say to “Solder the orange decoder wire to the motor terminal that was connected to the right-hand drive wheels, and the red wire to the wire that goes to those wheels.” Can I solder the orange and the red wires together to the motor mount since the motor terminal connects to the frame which is the pick up for the right-hand drive?
[xx(] Don’t do that!!! The idea (if I am understanding you correctly) is to have the decoder wired between the motor and the wheels picking up the track power. Make sure the motor is totally insulated from any possibility of picking up power from the rails. Follow the decoder instructions exactly and sucess will be yours. Be careful soldering so as to not heat the decoder. Also, some older engines made by Rivarossi and others powered the motor directly from the frame using only one wire to the motor. That is why you must be sure the motor is isolated. Electrical tape can be used for this. Watch this form for more of the same and perhaps more technical advice.
How old an engine and what wheel configuration is it?
I have installed decoders into Rivarossi Big Boy and Cab Forwards, as well as Berkshires and others, and they all had can motors.
The motor brushes must be totally isolated from the frame, and most of them already are if the two wires connected to the motor are easily accessible.
The red wire is the decoder’s power input for the right-hand rail as you look at the locomotive from the back as if you were sitting in the cab. The orange wire is the decoder’s output to the motor terminal that was originally connected to the right-hand wheels.
The decoder’s black wire is connected to the left-hand pickup wheels, and the gray wire goes to the motor.
Don’t connect red and orange together. If you do, you are shorting out the decoder and the engine will still run only on DC power.
The motor itself does not have to be isolated from the frame.
Just make certain both BRUSHES are isolated from the frame.