Furnace A/C Error Message E-1

Just to be clear, you're trying to get the Suburban propane furnace to work not the Dometic roof air conditioner right? 

The furnace does not need the a/c for it to work, but unfortunately in its infinite wisdom FR decided to change from a simple dedicated furnace thermostat to a fancy LCD model that also has to have connection to the a/c for it to work. The E-1 error is telling you that that a/c connection isn't there for some reason.

The furnace itself only needs a simple thermostat that closes a circuit when its calling for heat. That circuit is supplied by the furnace using two wires. If you identify those two wires and temporarily short them together the furnace should run. I suggest that you do that first so you know for sure where your problems are before tearing into the air conditioner.

I posted a link to the furnace manual earlier. If you aren't comfortable reading that to ID the right wires  maybe you can get your friend who does HVAC work to come back and do that for you.

You will need 12V power to test the furnace. The blower that's not working is the furnace blower, yes? Do your other 12V loads (lights, bath vent fan, water pump, etc) work? 

If you can confirm that your furnace is OK you can try to dig into the a/c controls or you might want to just install a simple cheap 2 wire furnace thermostat and get rid of the unnecessary complexity that FR has decided to do. That's what my 2015 179 has and it works perfectly well. Complicated isn't necessarily better, its usually the opposite. Like this:

https://www.amazon.com/Suburban-161154-Wall-Thermostat/dp/B003VB0YEC/ref=asc_df_B003VB0YEC/?tag=hyprod-20&linkCode=df0&hvadid=242042684287&hvpos=&hvnetw=g&hvrand=14856842385697236832&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9008704&hvtargid=pla-582577147814&psc=1

Not off topic at all, it will operate the furnace only. I was suggesting it for Tearless because it sounds like he is under the gun to get the furnace in his trailer working for his guests. 

The a/c's on the older rpods (like my 2015 179) have their tstats inside the interior a/c cover. I don't know what would be required to get a simple thermostat working in the newer Dometic a/c's, but I'd guess there would be a way. 

I'm with you on simplicity, some things have just gotten way more complicated than necessary. Thermostats are one of them in my opinion. The manufacturers seem to be in a race to add "features" most of which most folks will never fully understand much less use, especially not in a travel trailer.

The British have a great phrase they use for the preference for simple solutions that get the job done, "cheap and cheerful" they call it. Says it all I think. 

As Forrest Gump says, "stupid is as stupid does". Since the a/c in rpods is not a heat pump there is zero benefit -none- in having a complex control system that integrates the furnace and the a/c. Unlike in your house where you might need a control system to switch between heat pump and furnace operation automatically based on outside air temp, no one is ever going to run both at the same time in the trailer. It just makes both more prone to failure and confusion. If the circuit board doesn't work I would just get a dedicated simple thermostat for each piece of equipment and call it good, it will improve maintenance troubleshooting and simplify operation going forward.