Keith, Hopefully I can help you. I too have an interstate 19.
Regarding the redlight switch that does not go out near the entry door.
Obviously, the
12v system is up and running.
Go to the rear doors, open, to the left is the main battery switch. Rotate it all the way to the left. THERE WILL BE RESISTANCE. This shuts off all the
12v house power. Including the Czone.
Now, go to the switch by the door. The light should be out.
Hold the switch, and the power will go on.
So now, it should go out when you switch it off.
In short the rotary dial in the back has an electric motor that engages or disengages the switch. Turning in off manually, then turning it back on from the front switch SHOULD reset it. Let me know if this helps!!!