(((((((Hi all,
Im going to jump in here as I am also in the same situation as the original question describes, and still trying to trace our the issue. Our answers may be related.
In my van (92 Dodge Ram Van 3500 series converted by the now defunct Coachmen conversions division) the "house" power switch does absolutely nothing that i can tell. I have two 12v transfer coils (one front battery, one rear battery) that ive replaced with new along with their in line breakers as i suspected that was the issue (and was part, one breaker tested bad) but still didnt give me power to the "house." the "house" 12v works on 120 and works if i jump out the rear coil, but no other way. the converter appears good. the brand new transfer coil isnt opening with the 12v house switch like i expected.. all the breakers and fuses (ive yet found) are good or have been replaced.
Im going to try (again) and trace out the path of the house 12v switch, and see where it feeds from. are these things truly random or is there a general location where it can "usually" be found to feed from? all the wiring for this is hidden so any experienced tips will be helpful. )))))
If your setup is similar to my van conversion 'HOUSE' switch is used when you are connected to city power and takes 12 volt out of the circuit, activates the charger, and powers any 120 volt outlets you have. At least that's how mine works.....
Hope this helps and apologize in advance if I misunderstood you!
"We are not defined by our limitations, we are defined by our potential"