How do you add more functions to a decoder?
alloboard,
Easy: By purchasing a decoder with more functions.
Most decoders come with either 2-, 4-, or 6-function capability and are specific to lighting. 2-function will give you front and rear lighting. Additional functions add more sophisticated lighting "effects" like Mars and ditch lighting.
The "functions" are built into the circuit board of the decoder. You can't just "add" additional functions to a decoder.
Hope that helps...
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
Or you can buy a function-only decoder such as the Digitrax TL1 or TF4.
Depending on the situation, that might be a better alternative than ripping out and replacing an existing decoder.
It all depends on what you have and what you're trying to accomplish.
How will I wire a function only decoder with an existing decoder?
alloboardHow will I wire a function only decoder with an existing decoder?
The red and black leads go to the pickups/track power the same as with the existing decoder, and the other leads are wired to the additional functions (lights, etc) in the same general way as the functions on the existing decoder are wired.
But based on the nature of your question, it doesn't seem that you've read the instructions for the function-only decoders at the links I provided, or for any other function-only decoders. I'd strongly suggest that you do so.