Sorry to hear about the hospital visit, that's never a good thing!
You can't use the ERR RS Commander chuff input with the Chuff-Generator. The ERR RS Commander REQUIRES a totally isolated chuff switch, it cannot have a common ground! The Chuff-Generator and Super-Chuffer both use a ground referenced input, as does the R4LC used in the ERR Cruise Commander.
Truthfully, I find that it's almost always much easier to put the Super-Chuffer in the locomotive, you just need to pipe the chuff signal back to the tender.
My "standard installation" for a tender resident Cruise Commander install has the following seven leads in the tether.
- Center Roller
- Wheels
- Motor (1)
- Motor (2)
- Smoke Power
- Headlight
- Chuff
If you have the Super-Chuffer in the tender, you have all sorts of extra wiring to deal with to the locomotive. With all the other stuff in the tender, there's almost no scenario I can imagine that you couldn't fit the Super-Chuffer in the locomotive, and that's where it really should be.